…follow-up #4319)

Closes the ws.ts:613 TOCTOU thread that PR 18 (`WorkspaceFileSystem`)
flagged and that F1 (#4319) deliberately left to a follow-up by
shipping only the `BridgeFileSystem` injection seam in `BridgeClient`.

Pre-fix, ACP `writeTextFile` / `readTextFile` calls landed in
`BridgeClient`'s inline `fs.realpath` / `fs.writeFile` / `fs.readFile`
proxy, bypassing PR 18's defensive layer (trust gate, symlink
resolution, atomic temp-file write, line/limit windowing, audit emit).
HTTP `POST /file` / `GET /file` already routed through that layer —
agent fs and HTTP fs diverged in posture.

Changes
- New `bridgeFileSystemAdapter.ts` (~110 LOC): thin translation from
  ACP `WriteTextFileRequest` / `ReadTextFileRequest` to
  `WorkspaceFileSystem.resolve` → `writeText` / `readText`. Drops
  ACP-wire `null` line/limit (PR 18 wants `undefined`). Routes labeled
  `'ACP writeTextFile'` / `'ACP readTextFile'` so the unified audit
  stream can distinguish agent fs from HTTP fs at the consumer side.
- `runQwenServe.ts` + `server.ts`: construct `fsFactory` BEFORE the
  bridge default and pass `fileSystem: createBridgeFileSystemAdapter(fsFactory)`
  into `BridgeOptions`. Same factory instance feeds both HTTP fs
  routes and ACP fs → single operator audit stream covers both.
- New `bridgeFileSystemAdapter.test.ts` (10 tests, all pass): happy
  paths (trusted write + read), trust-gate deny, boundary rejection
  (writes + reads outside workspace), line/limit window, null→undefined
  normalization, `factory.forRequest` audit-context wiring (sessionId
  forwarded, omitted when ACP request lacks one).

Backward compatibility
- `BridgeOptions.fileSystem` was already optional in F1 (seam-only);
  embeds that don't pass it (or that pre-date this commit) keep using
  `BridgeClient`'s inline raw-fs proxy as before. This commit only
  changes the *default* `createServeApp` + `runQwenServe` wiring.

Verification
- `vitest run src/serve/`: 18 files, 746/746 tests pass (includes
  the 10 new adapter tests + the 175-test `httpAcpBridge.test.ts` that
  exercises the seam through `BridgeOptions.fileSystem`).

…rebased onto F1]

Squashed F3 implementation rebased from origin/main onto
daemon_mode_b_main (post-F1 #4319). F1 lifted the bridge core to
@qwen-code/acp-bridge package; F3's edits to the pre-F1
httpAcpBridge.ts BridgeClient class + factory were ported to the
new file locations:

  - BridgeClient.requestPermission rewrite → bridgeClient.ts
  - Factory mediator construction / pendingPermissions deletion /
    cancelPendingForSession refactor / respondTo*Permission
    rewrites / pendingPermissionCount + permissionPolicy getters /
    teardown sites (closeSession, killSession, shutdown drain)
    → bridge.ts
  - Error class re-exports → cli/src/serve/httpAcpBridge.ts shim
    (added CancelSentinelCollisionError, PermissionForbiddenError,
    PermissionPolicyNotImplementedError to the F1 re-export block)

This commit folds 13 logical F3 commits + 4 review fold-ins (Copilot
inline comments + 3 final-pass agent reviews) into a single
post-rebase squash. The full review trail is in
.claude/plans/fluttering-coalescing-kettle*.md (worktree-local).

Strategies (4): first-responder (default, byte-for-byte preserved),
designated, consensus (default N=floor(M/2)+1), local-only.

New SSE events: permission_partial_vote, permission_forbidden.
Capability tag: permission_mediation (always-on with build-supported
modes list); active policy at /capabilities.policy.permission.

Settings: policy.permissionStrategy enum + policy.consensusQuorum
number, both requiresRestart: true (F3 v1 reads at boot).

3 new typed errors: PermissionForbiddenError → 403,
PermissionPolicyNotImplementedError → 501 (forward-compat for future
policy literals), CancelSentinelCollisionError → 500 (agent / daemon
contract violation).

Hardness invariants: N1 synchronous-register, N2 cleanup ordering,
N3 originatorClientId stamping, O5 cancel sentinel pre-publish
collision check, O8 pre-F3 permission_resolved wire shape preserved.

Tests: 35 mediator unit + 10 audit ring + 56 SDK reducer + 6
bridgeClient + 3 bridge integration. Pre-existing
httpAcpBridge.test.ts cross-session-vote suite passes byte-for-byte.

Issue: #4175 (F3)

…fo fix (#4334)

* fix(acp-bridge): use channelInfoForEntry in closeSession + killSession (#4325)

Folds in the deferred fix from F1 (#4319) for #4325. Pre-fix both
methods captured `const ci = channelInfo` — the module-scoped CURRENT
attach target — rather than `channelInfoForEntry(entry)`. The two
diverge during the channel-overlap window (A dying, B freshly spawned
as `channelInfo`), where closing or killing a session whose
`entry.channel = A` would:

  1. Skip `A.sessionIds.delete()` because `B.channel !== A.channel`,
     leaving A's `sessionIds` set pinned past the close;
  2. Call `markSessionClosed` on **B**'s client instead of **A**'s,
     evaluating B's kill condition with stale assumptions about its
     session count — potentially killing B unnecessarily and forcing
     a third spawn cascade.

Other session methods in the same factory (`setSessionApprovalMode`
at ~L2609, `requestSessionStatus` at ~L1245) already use the
`channelInfoForEntry(entry)` helper; this brings `closeSession` and
`killSession` in line with that pattern.

Net change: 2 lines (one in each method) replaced; surrounding
comment blocks updated to document the channel-overlap rationale +
the matching sibling-method consistency argument.

## Why the smoke test rather than a full overlap regression

The exact bug-triggering state is hard to construct deterministically
under the current factory architecture:

  - A only flips `isDying = true` when its `sessionIds` drains to 0
  - The drain path (`killSession` or `closeSession` on the last
    session) also removes the session from `byId` synchronously
  - So by the time `channelInfo` could move to B, every session that
    was on A is gone from `byId` and thus unreachable to a subsequent
    `closeSession`

A faithful overlap regression test requires a test-only factory
inspection seam (manual `channelInfo` override, or a hook into
`aliveChannels` mutation). Adding that seam is non-trivial and
expands the bridge's public surface — out of F1-followup scope.

What this commit ships:

  - The 2-line fix itself (matches the sibling-method pattern; the
    correctness argument is structural, not race-empirical)
  - A smoke regression test at `httpAcpBridge.test.ts` exercising
    `closeSession` on the normal single-channel case and asserting
    the kill-on-last-session cascade fires correctly — would fail
    trivially if a future refactor reverted to module-scoped
    `channelInfo` capture without thinking through the
    `channelInfoForEntry → undefined` case
  - Inline comments at both fix sites + on the new test documenting
    why the full overlap repro is deferred

A follow-up issue can track adding the factory inspection seam +
the deterministic overlap regression test if anyone needs the
empirical guard rather than the structural one.

- 175/175 cli httpAcpBridge tests pass (174 existing + 1 new #4325 smoke)
- 62/62 acp-bridge tests pass (no regression)
- typecheck + eslint clean
- Closes #4325

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* feat(serve): wire WorkspaceFileSystem into BridgeFileSystem seam (F1 follow-up #4319)

Closes the ws.ts:613 TOCTOU thread that PR 18 (`WorkspaceFileSystem`)
flagged and that F1 (#4319) deliberately left to a follow-up by
shipping only the `BridgeFileSystem` injection seam in `BridgeClient`.

Pre-fix, ACP `writeTextFile` / `readTextFile` calls landed in
`BridgeClient`'s inline `fs.realpath` / `fs.writeFile` / `fs.readFile`
proxy, bypassing PR 18's defensive layer (trust gate, symlink
resolution, atomic temp-file write, line/limit windowing, audit emit).
HTTP `POST /file` / `GET /file` already routed through that layer —
agent fs and HTTP fs diverged in posture.

Changes
- New `bridgeFileSystemAdapter.ts` (~110 LOC): thin translation from
  ACP `WriteTextFileRequest` / `ReadTextFileRequest` to
  `WorkspaceFileSystem.resolve` → `writeText` / `readText`. Drops
  ACP-wire `null` line/limit (PR 18 wants `undefined`). Routes labeled
  `'ACP writeTextFile'` / `'ACP readTextFile'` so the unified audit
  stream can distinguish agent fs from HTTP fs at the consumer side.
- `runQwenServe.ts` + `server.ts`: construct `fsFactory` BEFORE the
  bridge default and pass `fileSystem: createBridgeFileSystemAdapter(fsFactory)`
  into `BridgeOptions`. Same factory instance feeds both HTTP fs
  routes and ACP fs → single operator audit stream covers both.
- New `bridgeFileSystemAdapter.test.ts` (10 tests, all pass): happy
  paths (trusted write + read), trust-gate deny, boundary rejection
  (writes + reads outside workspace), line/limit window, null→undefined
  normalization, `factory.forRequest` audit-context wiring (sessionId
  forwarded, omitted when ACP request lacks one).

Backward compatibility
- `BridgeOptions.fileSystem` was already optional in F1 (seam-only);
  embeds that don't pass it (or that pre-date this commit) keep using
  `BridgeClient`'s inline raw-fs proxy as before. This commit only
  changes the *default* `createServeApp` + `runQwenServe` wiring.

Verification
- `vitest run src/serve/`: 18 files, 746/746 tests pass (includes
  the 10 new adapter tests + the 175-test `httpAcpBridge.test.ts` that
  exercises the seam through `BridgeOptions.fileSystem`).

* fix(serve): preserve mode + atomic write for ACP writeTextFile (#4334 Copilot review)

Adopts Copilot's finding on PR #4334 (security-relevant):
#4334 (comment)

Pre-fix, the adapter routed ACP writeTextFile through
`WorkspaceFileSystem.writeText` which has no mode handling — new files
got umask-default (typically 0o644) and existing-target mode wasn't
preserved. The `BridgeFileSystem` contract requires 0o600 for new
files (NOT umask) and target mode preservation (a 0o600 secret edit
must stay 0o600). The old inline `BridgeClient.writeTextFile` proxy
did this; the adapter regressed it.

Fix: add a new `writeTextOverwrite` primitive to PR 18's
`WorkspaceFileSystem` (Approach B from the design discussion — picked
over CAS-in-adapter because the "unconditional create-or-overwrite
with mode preservation" semantic will recur in F4 TUI/IDE adapters
and future webhook integrations; cleaner to land it as a reusable PR
18 primitive now than retrofit later).

Implementation
- `WorkspaceFileSystem.writeTextOverwrite(p, content, opts?)` —
  unconditional create-or-overwrite, no expectedHash gate. Reuses the
  existing `atomicWriteTextResolvedFile` infrastructure via a new
  `WriteMode = 'overwrite'` variant: tolerates missing target (returns
  empty mode → 0o600 default), rejects symlinks (`symlink_escape`),
  preserves existing mode bits (`chmod` to `targetState.mode ?? 0o600`
  in line 1450). Path-locked the whole window; emits the same
  `fs.access` audit as `writeText` / `writeTextAtomic`.
- `assertAtomicTargetPrecondition` gains an `'overwrite'` branch that
  stats the target, returns its mode for preservation, and tolerates
  ENOENT (new file path); rejects symlinks / non-regular files in
  parity with `'replace'`.
- `validateWriteTextAtomicOptions` accepts `'overwrite'` mode WITHOUT
  expectedHash — that's the whole point of the new primitive (callers
  whose wire format has no client-side hash, like ACP).
- `atomicWriteTextResolvedFile`'s rename branch handles `'overwrite'`
  automatically (falls through to `renameWithRetryLocal` like
  `'replace'`; rename both clobbers existing and creates new).

Adapter switch
- `bridgeFileSystemAdapter.ts:96` — `wfs.writeText(resolved, content)`
  → `wfs.writeTextOverwrite(resolved, content)`. Updated docstring
  explains why this primitive over `writeText` (no mode) or
  `writeTextAtomic` (CAS gate doesn't fit ACP's hash-less wire).

Contract update
- `bridgeFileSystem.ts:61-93` — `writeText` doc now reflects the
  production posture: write-then-rename atomicity, target mode
  preservation, 0o600 default for new files, **symlink rejection**.
  The pre-F1 inline proxy resolved symlinks and wrote through to the
  target; PR 18 + HTTP `POST /file` (PR 20) reject them. The adapter
  now matches that posture, so ACP fs and HTTP fs behave identically
  — a divergence from pre-F1 ACP semantics, called out explicitly.

Tests (+10, 81 passing on touched files)
- workspaceFileSystem.test.ts: writeTextOverwrite creates new file at
  0o600, preserves existing target mode (0o600 secret stays 0o600),
  preserves +x executable bit, rejects post-resolve symlink swap with
  symlink_escape, enforces trust gate, emits fs.access.
- bridgeFileSystemAdapter.test.ts: through-adapter assertions that
  new files land at 0o600 and existing 0o600 secrets stay 0o600 after
  agent overwrite. Skipped on Windows (POSIX permission bits not
  honored). Symlink rejection is covered at the lower workspaceFileSystem
  layer to avoid duplicating the post-resolve-swap setup.

* fix(serve): 4 wenshao review fold-ins on #4334 (2 Critical + 2 Suggestion)

All four threads from the wenshao review round on PR #4334 (Qwen
`/review`) — adopted as-suggested with the fixes outlined below.

**[Critical] writeTextOverwrite blocks on large/binary existing files**
(`workspaceFileSystem.ts:849` thread r3270664710)

`readExistingTextMeta(p)` reads the existing file just for encoding /
BOM / line-ending hints (best-effort meta). My earlier catch only
swallowed `ENOENT`, so `file_too_large` (>256 KiB) and `binary_file`
errors propagated and **blocked the overwrite entirely**. Pre-PR ACP
`BridgeClient.writeTextFile` never read the existing file at all —
an agent overwriting a 1 MiB log or binary config would have always
succeeded. Bubbling those classified errors regressed that.

Fix: catch ENOENT + file_too_large + binary_file; leave `existingMeta`
undefined and let `mergeWriteMeta` fall back to UTF-8/no-BOM/LF
defaults. New tests cover both scenarios.

Side fix uncovered while writing the tests: `created` was derived from
`existingMeta === undefined` which is wrong after this catch widening
— a binary or too-large existing file would now report `created: true`.
Replaced with an explicit `lstat` to detect target existence
independently of meta-read success.

**[Critical] writeTextAtomic({mode:'overwrite'}) is unsupported**
(`workspaceFileSystem.ts:146` thread r3270664723)

`WriteMode` was widened to include `'overwrite'` and
`validateWriteTextAtomicOptions` accepted it — but
`writeTextAtomic`'s `existingMeta` branch only reads meta for
`mode === 'replace'` AND `created: opts.mode === 'create'` is
hard-coded so `'overwrite'` always reports `created: false` even for
new files. Direct callers of `writeTextAtomic({mode: 'overwrite'})`
would silently lose CRLF on Windows files and misreport new-file
creation. The dedicated `writeTextOverwrite()` method handles both
correctly and is the only supported entry point for
unconditional-overwrite semantics.

Fix (option b from the reviewer): reject `'overwrite'` in
`validateWriteTextAtomicOptions` with a `parse_error` that names the
correct method. The `WriteMode` union still admits `'overwrite'`
internally (so `atomicWriteTextResolvedFile` + `assertAtomicTarget
Precondition`'s 'overwrite' branch compile), but no external caller
can reach those code paths via `writeTextAtomic`. The error message
points to `writeTextOverwrite()` so misuse surfaces an actionable hint.

**[Suggestion] killSession #4325 fix missing symmetric regression test**
(`httpAcpBridge.test.ts:6421` thread r3270664724)

The earlier #4325 fix touched both `closeSession` AND `killSession`
(both `const ci = channelInfo` → `const ci = channelInfoForEntry(entry)`)
but the smoke test only exercises closeSession. A future refactor
reverting `killSession` alone would pass all existing tests.

Fix: add a symmetric `killSession` smoke test mirroring the closeSession
shape — single-channel kill → assert handle.killed + sessionCount = 0.
Same overlap-race caveat documented inline. Future deterministic
overlap test still deferred to the same follow-up that adds factory
inspection seams.

**[Suggestion] createServeApp default `trusted: false` silently rejects
agent writes for embeds** (`server.ts:257` thread r3270664727)

`createServeApp` constructs its default `fsFactory` with
`trusted: false` (test-safe posture), and now wires it into the
bridge via `createBridgeFileSystemAdapter(fsFactory)`. Pre-PR ACP
`writeTextFile` went through the inline raw-fs proxy which had no
trust gate. Any embed using `createServeApp` without providing
`deps.fsFactory` or `deps.bridge` will now have ALL agent writes
silently reject with `untrusted_workspace`. `runQwenServe` consumers
are unaffected (defaults `trusted: true`), but IDE companions /
hosted daemons calling `createServeApp` directly are at risk.

Fix: emit a stderr startup warning when `deps.fsFactory` is not
provided, explicitly naming the asymmetry and the three opt-out
paths (provide fsFactory, provide bridge, or accept the gate). Visible
to operators so the trust-gate-default isn't an opaque "writes
silently fail" mystery in production.

Additional test gaps closed (sub-bullet from r3270664724):
- adapter-level `readText` trust-gate parity check — verifies that
  `trusted: false` does NOT extend to reads (PR 18's trust gate is
  write-only). A future refactor mistakenly gating reads would only
  fail HTTP-fs tests, not adapter ones.
- `writeTextOverwrite` non-regular-file rejection — pins the
  `parse_error` posture for directory targets so a relaxation in
  `assertAtomicTargetPrecondition`'s 'overwrite' branch is caught.

Verification
- `npx vitest run packages/cli/src/serve/` — 18 files, 760/760 pass
  (+6 new tests over the previous 754)
- `cd packages/acp-bridge && npx vitest run` — 5 files, 62/62 pass
- Pre-commit (`prettier --write` + `eslint --fix --max-warnings 0`)
  clean on all 5 staged files

* fix(serve): 4 more wenshao fold-ins on #4334 (1 Critical + 3 Suggestion)

Adopts 4 of 7 wenshao review threads on PR #4334. The remaining 3
(1 Critical + 2 placeholder) are surfaced separately for user
judgment — the Critical's suggested fix doesn't work as-is and needs
a design call; the 2 placeholders look like reviewer-tool tests
("JSDoc test." / "test").

**[Critical] EACCES/EPERM blocks overwrite** (r3270921396, ws.ts:877)

The earlier r3270664710 fix widened the meta-read catch to swallow
ENOENT + file_too_large + binary_file. wenshao caught that EACCES /
EPERM also need to be swallowed — a file the daemon can't read
(0o000, other-user-owned) would abort the overwrite, contradicting
the "best-effort meta read" comment. Also opens an agent-side probe:
an attacker could detect file readability by observing EACCES on
overwrite attempts.

Fix: extend the catch to also swallow EACCES + EPERM. Comment block
expanded to spell out the full set (ENOENT / EACCES / EPERM /
file_too_large / binary_file) and the probing-defense rationale.

Test: `writeTextOverwrite succeeds over an existing 0o000 (unreadable)
file` — pins the posture so a regression here is caught. Skipped on
Windows + when running as root (root bypasses POSIX mode bits).

**[Suggestion] Negative `limit` produces wrong content**
(r3270921401, bridgeFileSystemAdapter.ts:112)

Pre-PR the inline `BridgeClient.readTextFile` returned `{ content:
'' }` for `limit <= 0`. PR 18's `readText` applies `slice(0, limit)`,
which for `limit: -1` returns "all lines except the last" — wrong
content. Same hazard for non-positive `line` (PR 18 rejects with
`parse_error` for `line < 1`, smuggling a 4xx-shaped error to agents
that previously got `''`).

Fix: tighten the adapter's `typeof === 'number'` guard to also
require `> 0`. Comment expanded to call out the divergence and why
"drop and let PR 18 default to no-windowing" is the closest match to
pre-PR empty-content posture without leaking parse_error.

Tests: `drops non-positive limit (negative / zero) instead of
forwarding` + `drops non-positive line (zero) instead of forwarding
parse_error`.

**[Suggestion] Warning fires when deps.bridge is provided**
(r3270921402, server.ts:266)

Earlier r3270664727 fix added a startup stderr warning when
`deps.fsFactory` is not provided. wenshao caught that the warning
also fires when `deps.bridge` IS provided — but in that case the
embed owns its own fileSystem wiring (the default adapter never
runs), so the warning's claim about ACP writes rejecting is false.

Fix: narrow guard to `!deps.fsFactory && !deps.bridge`. Comment
expanded to explain why bridge-injection suppresses the warning.

**[Suggestion] No oversized-payload test for writeTextOverwrite**
(r3270921399, ws.ts:835)

`writeTextOverwrite` calls `enforceWriteSize(decodedSizeBytes)`
mirroring `writeText`'s 5 MiB cap, but the existing oversized-write
test only exercises `writeText`. A regression dropping the check on
the new method would let agents (the primary consumer) write
arbitrarily large files undetected.

Test: `writeTextOverwrite rejects content exceeding MAX_WRITE_BYTES
with file_too_large`.

Verification
- `npx vitest run packages/cli/src/serve/` — 18 files, 764/764 pass
  (+4 new tests over the previous 760)
- Pre-commit (`prettier --write` + `eslint --fix --max-warnings 0`)
  clean on all 5 staged files

* fix(serve): 4 wenshao/deepseek fold-ins on #4334 (1 Critical refactor + 3 Suggestion)

Adopts 4 of 5 new threads from the DeepSeek-v4-pro review round on
PR #4334 (Qwen `/review`). The 5th (DWcK8) is a duplicate of a test
already in commit 9f73b83 — declined separately with a pointer.

**[Critical] Trust-default asymmetry between runQwenServe ↔ createServeApp**
(r3270978579, server.ts DWcK4)

`runQwenServe.ts` defaults `trusted: true` (production daemon),
`server.ts` defaults `trusted: false` (test-safe). The asymmetry is
intentional but lives in two places — a future maintainer can break
the alignment without any compile-time signal. The earlier stderr
warning (commit e185409) covers the embed-omits-fsFactory case but
NOT a regression in the runQwenServe → createServeApp pass-through.

Fix: extract `resolveBridgeFsFactory(input)` helper in `server.ts`
(exported alongside `createDefaultFsAuditEmit`). Both call sites use
it. Trust stays a REQUIRED parameter — the policy difference is
preserved at the call sites, but the construction shape (build vs
inject + audit-emit default) is centralized. Defense-in-depth, not
behavior change.

**[Suggestion] adapter JSDoc claim about `mapDomainErrorToErrorKind`
is misleading** (r3270978595, DWcLB)

The docstring at `bridgeFileSystemAdapter.ts:38` says "the bridge's
existing `mapDomainErrorToErrorKind` classifier downstream picks up
`FsError` codes". This is false: `mapDomainErrorToErrorKind` in
`acp-bridge/src/status.ts` checks `instanceof` / `.name` / `.code`
(Node errno names), but has NO branch reading `err.kind` (FsError's
discriminator: `untrusted_workspace` / `symlink_escape` / etc.).
Errors still propagate (the `.kind` field rides through on the
thrown FsError object itself), but a future maintainer debugging
error classification during an incident would chase the wrong code
path.

Fix: rewrite the docstring to describe the actual flow — `FsError`
is thrown unchanged through BridgeClient's ACP handlers; downstream
consumers reading the ACP error payload key on `.kind` directly. The
HTTP `sendFsError` serializes the same `.kind`, so SDK consumers see
the same shape from either surface. Adding a real `instanceof
FsError` branch to `mapDomainErrorToErrorKind` would need cross-
package imports (FsError lives in `cli/src/serve/fs`, classifier in
`acp-bridge`) — explicitly deferred to a separate PR.

**[Suggestion] adapter readText error propagation untested**
(r3270978593, DWcK_)

Read-side errors from `wfs.readText` (`file_too_large`,
`binary_file`, `symlink_escape`) propagate untested through the
adapter — the existing tests cover trust-gate (already write-only),
line/limit forwarding, null/non-positive guards, and boundary, but
not the `FsError` classes themselves. A regression silently
swallowing or wrapping them would only fail HTTP-fs tests.

Fix: add 3 adapter tests pinning `file_too_large` / `binary_file` /
`symlink_escape` propagation surface as-is via the adapter's
re-thrown error.

**[Suggestion] channelInfoForEntry HAZARD comments on bridge.ts fix
sites** (r3270978598, DWcLD)

The regression test for the `#4325` fix
(`httpAcpBridge.test.ts:6421`) is single-channel smoke only — its
own comment acknowledges "a reverted fix that captured `channelInfo`
after the entry was gone from `byId` would also pass this assertion".
The actual overlap-race state isn't deterministically constructable
without factory-internal hooks. Until the deterministic test lands,
the only defense against accidental revert is code-review visibility.

Fix: add `HAZARD(#4325)` comments at both `closeSession` and
`killSession` fix sites in `acp-bridge/src/bridge.ts`, explicitly
flagging that the existing smoke test would not catch a revert and
that the `channelInfoForEntry(entry)` call must NOT be refactored
away without first landing the deterministic overlap test.

Verification
- `npx vitest run packages/cli/src/serve/` — 18 files, 767/767 pass
  (+3 new adapter tests; the prior 760→767 includes runs of multi-
   tick fold-ins on the same branch).
- `cd packages/acp-bridge && npx vitest run` — 5 files, 62/62 pass
- Pre-commit (`prettier --write` + `eslint --fix --max-warnings 0`)
  clean on all 5 staged files

* fix(serve): 4 more wenshao fold-ins on #4334 (DWrbe/DWrbl/DWrbn/DWrbr)

Adopts the second round of DeepSeek-v4-pro suggestions on PR #4334.
All 4 are small, targeted improvements without controversy.

**DWrbe — WriteMode admits 'overwrite' at compile time** (r3271063030)

`WriteTextAtomicOptions.mode` was typed as `WriteMode` (which
includes 'overwrite'), but `validateWriteTextAtomicOptions` throws
`parse_error` for that value. The runtime error catches misuse but
TypeScript happily lets the call through.

Fix: introduce `AtomicWriteMode = Exclude<WriteMode, 'overwrite'>`
public type and narrow `WriteTextAtomicOptions.mode` to it. Runtime
validator stays as defense-in-depth.

**DWrbl — boundary tests use bare .rejects.toThrow()** (r3271063040)

Both boundary-enforcement adapter tests asserted "throws" without
pinning the FsError kind. Incidental OS errors (CI container EACCES
on /etc/passwd) or future pre-check additions could pass these
tests trivially while masking that boundary enforcement isn't
firing.

Fix: assert `.kind === 'path_outside_workspace'` for both sides.

**DWrbn — trust warning floods stderr in tests** (r3271063045)

The startup warning fires on every createServeApp call. server.test.ts
calls createServeApp ~25 times, masking genuine failures.

Fix: module-scoped once-per-process guard `warnedDefaultTrust`. Module
scope (not per-app closure) because the warning is a posture statement
about this binary, not per-instance.

**DWrbr — channelInfoForEntry undefined is silent** (r3271063052)

closeSession / killSession's cleanup branches short-circuit silently
when channelInfoForEntry returns undefined (entry's channel torn
down). The "closing session" log fires but the skipped-cleanup fact
is invisible, making zombie-channel debugging harder.

Fix: emit stderr diagnostic naming session id + which method
short-circuited + likely cause. Sibling methods like
requestSessionStatus throw SessionNotFoundError; close/kill are
idempotent so we log instead.

Verification: serve 767/767, acp-bridge 62/62, pre-commit clean.

…4335)

* feat(acp-bridge): F3 — multi-client permission coordination (#4175) [rebased onto F1]

Squashed F3 implementation rebased from origin/main onto
daemon_mode_b_main (post-F1 #4319). F1 lifted the bridge core to
@qwen-code/acp-bridge package; F3's edits to the pre-F1
httpAcpBridge.ts BridgeClient class + factory were ported to the
new file locations:

  - BridgeClient.requestPermission rewrite → bridgeClient.ts
  - Factory mediator construction / pendingPermissions deletion /
    cancelPendingForSession refactor / respondTo*Permission
    rewrites / pendingPermissionCount + permissionPolicy getters /
    teardown sites (closeSession, killSession, shutdown drain)
    → bridge.ts
  - Error class re-exports → cli/src/serve/httpAcpBridge.ts shim
    (added CancelSentinelCollisionError, PermissionForbiddenError,
    PermissionPolicyNotImplementedError to the F1 re-export block)

This commit folds 13 logical F3 commits + 4 review fold-ins (Copilot
inline comments + 3 final-pass agent reviews) into a single
post-rebase squash. The full review trail is in
.claude/plans/fluttering-coalescing-kettle*.md (worktree-local).

Strategies (4): first-responder (default, byte-for-byte preserved),
designated, consensus (default N=floor(M/2)+1), local-only.

New SSE events: permission_partial_vote, permission_forbidden.
Capability tag: permission_mediation (always-on with build-supported
modes list); active policy at /capabilities.policy.permission.

Settings: policy.permissionStrategy enum + policy.consensusQuorum
number, both requiresRestart: true (F3 v1 reads at boot).

3 new typed errors: PermissionForbiddenError → 403,
PermissionPolicyNotImplementedError → 501 (forward-compat for future
policy literals), CancelSentinelCollisionError → 500 (agent / daemon
contract violation).

Hardness invariants: N1 synchronous-register, N2 cleanup ordering,
N3 originatorClientId stamping, O5 cancel sentinel pre-publish
collision check, O8 pre-F3 permission_resolved wire shape preserved.

Tests: 35 mediator unit + 10 audit ring + 56 SDK reducer + 6
bridgeClient + 3 bridge integration. Pre-existing
httpAcpBridge.test.ts cross-session-vote suite passes byte-for-byte.

Issue: #4175 (F3)

* fix(f3): build/capability fixes from Copilot review (#4335)

- packages/sdk-typescript/src/daemon/index.ts: re-export the four F3
  permission event types (`DaemonPermissionForbiddenData/Event`,
  `DaemonPermissionPartialVoteData/Event`) so the public package barrel
  at `src/index.ts` (which forwards them via `from './daemon/index.js'`)
  resolves at build time. Without this fix `npm run build
  --workspace=packages/sdk-typescript` failed with TS2305/TS2724;
  vitest passed only because it resolves TS source via tsx and
  bypasses tsc compilation. Reported in PR #4335 review comments
  3270615836 / 3270622302 (wenshao via Qwen Code /review).

- packages/cli/src/serve/server.test.ts: append `'permission_mediation'`
  to `EXPECTED_STAGE1_FEATURES` and adjust `EXPECTED_REGISTERED_FEATURES`
  reordering so the test fixture matches the registry's actual order
  (`...workspace_mcp_restart, require_auth, auth_device_flow,
  permission_mediation`). Without this fix four `serve capability
  registry` tests asserted via `.toEqual` against a stale list.

- docs/developers/qwen-serve-protocol.md: swap `permission_mediation`
  and `auth_device_flow` in the documented capability list so the order
  mirrors `SERVE_CAPABILITY_REGISTRY` declaration order.

- packages/vscode-ide-companion/schemas/settings.schema.json: regenerate
  the IDE-companion JSON schema with the new `policy` section (was
  pending from Commit 5 of the F3 series; checked in here so the
  IDE companion sees the same `permissionStrategy` / `consensusQuorum`
  shape that the CLI accepts).

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(f3): wire production audit ring + restore timeout stderr (#4335)

Wenshao review #4335 surfaced two related Critical findings:

1. **Audit publisher silently no-op in production** (3270622298). The
   `bridgeOptions.ts:305` JSDoc claimed "the bridge allocates an
   internal `PermissionAuditRing`" but the actual fallback at
   `bridge.ts:543` is `createNoOpPermissionAuditPublisher()`, and
   `runQwenServe.ts` never wired one. All 5 audit record types
   (`requested`, `voted`, `forbidden`, `resolved`, `timeout`) were
   silently discarded — the forensic audit trail the F3 plan
   committed to ("ring 留给后续 PR 加查询接口") never existed in
   any deployed daemon.

2. **Timeout breadcrumb lost** (3270622304). Pre-F3 wrote
   `"timed out after Xms"` to daemon stderr on every permission
   timeout. F3 removed that direct write and delegated to
   `audit.recordTimeout()`, but the audit publisher is the no-op
   fallback in production (see #1). Operators tailing daemon
   stderr could no longer observe permission timeouts.

Fixes:

- `runQwenServe.ts` allocates a `PermissionAuditRing` (default cap 512)
  + `createPermissionAuditPublisher` and passes the publisher via
  `BridgeOptions.permissionAudit`. The ring is held in the daemon
  host's closure for the lifetime of the daemon — a future
  `GET /workspace/permission/audit` route (out of F3 v1 scope) can
  lift it out for query without further bridge changes.

- `permissionMediator.ts` writes the stderr breadcrumb directly from
  the timer callback, before forwarding to the (potentially no-op)
  audit publisher. Wrapped in try/catch because `process.stderr.write`
  can synchronously throw on EPIPE — losing observability is
  preferable to crashing the timer queue.

- `bridgeOptions.ts` JSDoc rewritten to match reality: the bridge
  falls back to a no-op publisher; production wiring lives in
  `runQwenServe.ts`; the stderr breadcrumb is in the mediator
  (independent of the publisher).

- New unit test `writes a stderr breadcrumb when the timer fires`
  spies on `process.stderr.write` and asserts the breadcrumb format
  contains the requestId, sessionId, and the timeout duration so
  future refactors can't silently drop the line again.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(f3): drop dead helper + propagate originator to F3 view state (#4335)

Two small follow-ups from wenshao review #4335:

- **`bridge.ts:672-682` — dead `_resolutionToAcpResponse` helper**
  (3270622309). Defined and immediately suppressed with `void`. The
  identical `resolutionToAcpResponse` lives at `bridgeClient.ts:41`
  and is the one actually used by `BridgeClient.requestPermission`
  — the bridge-factory copy was a stranded leftover from the lift
  out of inline closures into the mediator pattern. Removed
  declaration, `void` statement, and the now-unused
  `RequestPermissionResponse` (`@agentclientprotocol/sdk`) and
  `PermissionResolution` (`./permission.js`) imports.

- **SDK reducer `mergeOriginator` for F3 events** (3270622311). The
  mediator stamps `originatorClientId` (= prompt originator per
  N3) on the `permission_partial_vote` / `permission_forbidden`
  envelope, but the reducer cases used `next.push({ ...event.data })`
  which only copies `data` fields. SDK consumers reading
  `permissionVoteProgress[reqId]` / `forbiddenVotes[i]` could not
  determine which client's prompt was targeted by the partial-vote
  progress / forbidden vote — same gap PR #4282 fixed for
  approval-mode / tool-toggle / workspace-init / mcp-restart.

  Applied the existing `mergeOriginator` helper to both reducer
  cases. Added `originatorClientId?: string` to both Data
  interfaces with JSDoc explaining the propagation contract
  (preserve any pre-existing `data.originatorClientId`; otherwise
  stamp from the envelope; for forbidden votes the field is
  distinct from `data.clientId` which carries the rejected voter).

  Three new reducer tests:
  1. `permission_partial_vote` propagates envelope originator into
     `permissionVoteProgress`.
  2. `permission_forbidden` propagates envelope originator into
     `forbiddenVotes`, distinct from `data.clientId`.
  3. `mergeOriginator` preserves any pre-existing
     `data.originatorClientId` over the envelope value.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(f3): wenshao Round 4 — defensive stderr, audit accuracy, orphan cleanup (#4335)

Four findings from wenshao review #4324937255 — the Critical one
masked an actual hang scenario; the other three are observability /
correctness fixes that round out F3 v1.

**[Critical] safeEmit / safeAudit stderr breadcrumb wraps** (3271041461).
Both helpers wrote `process.stderr.write` inside their `catch` block
WITHOUT a nested `try/catch`. If stderr itself synchronously throws
(EPIPE during daemon shutdown), the exception escapes the "safe"
wrapper. In `resolveEntry`'s cleanup ladder
(`safeEmit → rememberResolved → safeAudit → pending.resolve`), an
escaping safeEmit exception aborts before `pending.resolve(resolution)`
runs — the request was already deleted from `this.pending` (no
double-resolve guard), so the agent's awaiting Promise never
settles. `requestPermission` hangs until the timeout fires. The
timer callback already wraps its breadcrumb in `try/catch` for the
same reason — applied the matching pattern to safeEmit + safeAudit.

**[Suggestion] Idempotent re-vote audit shows attempted optionId,
not the original** (3271041464). When `client_A` originally voted
for `proceed_once` and later attempts `proceed_always`, the tally
silently keeps `proceed_once` (idempotent) but the audit ring
recorded `optionId: proceed_always`. An operator reading the ring
would see a vote for proceed_always that never counted toward
quorum. Look up the originally-voted option from the tally and
substitute it into the audit record. Added regression test
asserting the audit reflects tally state.

**[Suggestion] SDK reducer leaks `permissionVoteProgress` on
mid-permission reconnect** (3271041465). When an SDK client
reconnects and misses `permission_request`, then receives
`permission_partial_vote` (stored in `permissionVoteProgress`),
then receives `permission_resolved` — the early-return path on
unmatched `requestId` did NOT clear `permissionVoteProgress`. The
orphan progress entry persisted until session end. Both
`permission_resolved` and `permission_already_resolved` reducer
cases now unconditionally clear any orphan entry on the unmatched
path. Two new reducer tests cover the recovery contract; the
misleading "the next `permission_resolved` will clear both"
comment on `permission_partial_vote` is corrected.

**[Suggestion] Document votersAtIssue snapshot timing window**
(3271041469). The snapshot fires synchronously after
`entry.events.publish`, with no event-loop yield between, so a NEW
HTTP client cannot register between publish and snapshot. But an
SSE-only subscriber (no `X-Qwen-Client-Id` registered yet) that
connected BEFORE publish is invisible to the snapshot — `consensus`
silently rejects its later vote as `forbidden`. Documented the
window in `votersForSession` JSDoc; future PRs surfacing
`eligibleVoters[]` on `permission_request.data` should source it
from the same snapshot for consistency. No code change — the
narrow window is acceptable for F3 v1, and the structural fix
(snapshot at publish time) requires bridge-level refactor.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(f3): wenshao Round 5 — sentinel injection guard, observability, /8 loopback (#4335)

Four findings from wenshao review #4325130053. The Critical one is
a real security gap; the others are observability + correctness
hardening.

**[Critical] Cancel sentinel injection bypass** (3271185588). The
mediator's `vote()` recognizes `CANCEL_VOTE_SENTINEL` BEFORE
validating the option against `allowedOptionIds`, so a wire client
sending `{outcome:'selected', optionId:'__cancelled__'}` would
short-circuit ALL policy dispatch (designated originator check,
consensus quorum, local-only loopback gate). The mediator's JSDoc
documented the precondition ("callers MUST NOT forward an
incoming vote.optionId === CANCEL_VOTE_SENTINEL from a wire
client") but the precondition was never enforced — the bridge's
`respondToSessionPermission` mapped the wire optionId straight
through. Added an explicit `InvalidPermissionOptionError` throw
when the wire payload is `{selected, CANCEL_VOTE_SENTINEL}`. The
collision-defense at request issue time
(`CancelSentinelCollisionError`) already prevents agents from
advertising the sentinel as a legitimate option; this closes the
remaining vector.

**[Suggestion] Silent quorum cap + M=0 hang observability**
(3271185594). Two related diagnostic gaps in the consensus
policy:
- When `policy.consensusQuorum` exceeds `votersAtIssue.size`, the
  cap fires silently. Operators investigating "why did consensus
  resolve at N=2 when I configured 5?" had no breadcrumb.
- When `policy === 'consensus'` and `votersAtIssue.size === 0`,
  every vote rejects as `forbidden: designated_mismatch` because
  the empty snapshot can never match any voter clientId. The
  request hangs until `permissionTimeoutMs` with no
  diagnostic signal.

Added stderr breadcrumbs at both points: cap-applied (once per
request via a `consensusQuorumCapNoted` flag on `MediatorPending`)
and at issue time when consensus M=0. No semantic change — the
cap and the timeout-only resolution behavior are intentional per
the F3 plan; the breadcrumbs just make them debuggable.

**[Suggestion] detectFromLoopback misses 127.0.0.0/8** (3271185597).
Per RFC 1122 the entire `127.0.0.0/8` block is loopback. The
exact-match Set of three literals (`127.0.0.1`, `::1`,
`::ffff:127.0.0.1`) silently fail-CLOSED on legitimate
`127.0.0.2` / `127.0.1.1` / `::ffff:127.0.0.2` peers, causing
unexpected `remote_not_allowed` rejections under `local-only`
policy. Switched to a prefix test so the entire `/8` and its
dual-stack mirror are accepted. Direction stays fail-CLOSED for
unrecognized address shapes.

**[Suggestion] VSCode JSON schema integer/min validation**
(3271185604). `runQwenServe.ts` validates
`Number.isInteger(consensusQuorum) && >= 1`, but the generated
`settings.schema.json` declared `"type": "number"` so VSCode's
inline JSON Schema validation accepted `0` / `-1` / `1.5` and
the user only learned the value was invalid on the next daemon
restart. Added `jsonSchemaOverride: {type:'integer', minimum:1}`
to the `consensusQuorum` settings entry and regenerated the
schema. IDE editors now flag invalid values immediately.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(f3): Round 6 — wenshao APPROVED + DeepSeek follow-ups (#4335)

Mixed batch: bridge-test backfill from wenshao's APPROVED review
plus 4 DeepSeek/v4-pro suggestions and the 3 typecheck/test
blockers DeepSeek named in CHANGES_REQUESTED #4325674833.

**Pre-merge blockers (DeepSeek #4325674833 body)**

- `server.test.ts:529` `FakeBridge` — added the F3-required
  `permissionPolicy: 'first-responder' as const`. Tests don't
  exercise mediation; the literal pins the pre-F3 default so
  existing assertions stay shape-compatible.

- `server.test.ts:3994` `WorkspaceFileSystemFactory.forRequest()`
  mock — added the missing `writeTextOverwrite` method that PR
  #4334 introduced on `WorkspaceFileSystem` after this branch
  forked.

- 4 vote-context test failures from `fromLoopback` plumbing —
  updated the four `expect(...).toEqual(...)` assertions in
  `POST /session/:id/permission/:requestId` and
  `POST /permission/:requestId` to include `fromLoopback: true`
  on the captured context. The supertest peer is `127.0.0.1`,
  so `detectFromLoopback(req)` correctly stamps the field; the
  pre-F3 expected shape was stale.

**Inline suggestions adopted**

- **3271420267** (wenshao APPROVED, security-critical) — added
  bridge-level test `rejects cancel sentinel injection via
  {selected,'__cancelled__'}` in `httpAcpBridge.test.ts`. Without
  it, a future refactor could silently remove the wire-injection
  guard that closes the policy-bypass attack surface introduced
  in Round 5 (#3271185588). Required `npm run build
  --workspace=packages/acp-bridge` to refresh `dist/` before
  vitest picked up the F3 bridge.ts changes; documented for
  future contributors editing F3 acp-bridge code.

- **3271627444** (DeepSeek) — `request()` JSDoc rewritten to
  drop "Promise contract — never rejects" without qualification.
  The `CancelSentinelCollisionError` synchronous throw is real
  and intentional (a never-settling Promise alongside a thrown
  error is worse than fail-fast), but callers must be aware of
  it. Updated the contract doc to call out the sync-throw
  exception explicitly and documented that async callers get
  the throw via their own Promise machinery.

- **3271627446** (DeepSeek) — fixed "Bounded LRU" comment on
  `MAX_RESOLVED_PERMISSION_RECORDS` to "Bounded FIFO" since
  `rememberResolved` uses `resolvedOrder.shift()` (drop oldest).
  Mirrors the parallel `PermissionAuditRing` correction in
  commit b0242dd.

- **3271627457** (DeepSeek) — added stderr breadcrumbs to all 3
  forbidden-vote sites (voteDesignated / voteConsensus /
  voteLocalOnly). Audit ring is in-memory only (no v1 query
  route), SSE events are transient — operators tailing daemon
  stderr previously had zero indication of permission rejections.
  New `writeForbiddenStderr` helper centralizes the formatting
  + try/catch defensive posture (mirrors the timeout breadcrumb
  pattern from Round 4).

- **3271627459** (DeepSeek) — added a `TODO(forward-compat)`
  comment at `voteConsensus`'s rejection site documenting the
  `designated_mismatch` reason-code overload. The same wire
  string covers two distinct semantic cases: "voter is not the
  prompt originator" (designated policy) and "voter not in
  consensus votersAtIssue snapshot" (consensus). Splitting them
  into distinct codes is deferred to a future PR once an SDK
  consumer needs to disambiguate.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(f3): Round 7 — error precedence + 7 hardening fixes from wenshao (#4335)

8 findings from wenshao Round 7. The Critical one closes a session-
existence information leak; 6 Suggestions improve observability,
type safety, and test coverage; 1 documents the cancel-sentinel
escape hatch in the local-only setting description.

**[Critical] Error precedence regression in respondToSessionPermission**
(3271978329). When `peekSessionFor(requestId)` returned `undefined`
(timed out / LRU-evicted / never registered), the cross-session
guard at line 2033 didn't fire (`!== undefined` skips it), so
execution fell through to `resolveTrustedClientId` which throws
`InvalidClientIdError` (HTTP 400) when the caller's clientId
isn't registered. Pre-F3 returned `false` (HTTP 404) for unknown
requestIds regardless of clientId validity. Without the explicit
guard, a probe with a fabricated clientId could distinguish
"session exists with these registered clients" (400) from "no
such request" (404). Added an explicit `actualSessionId ===
undefined → return false` short-circuit BEFORE the clientId
validation. The defensive `unknown_request` switch case below
becomes unreachable in practice; left in place for defense-in-depth.

**[Suggestion] Cancel sentinel cross-policy escape hatch under
`local-only`** (3271978336). Documented in `voteLocalOnly` JSDoc
and the settings description that a remote voter can ABORT a
pending permission via `{outcome:'cancelled'}` even though they
cannot RESOLVE one. The F3 plan calls this out as intentional
(cross-policy cancel for consistency with first-responder /
designated / consensus); operators wanting strict-cancel-too need
a dedicated loopback-bound daemon. Doc-only — semantic change
deferred.

**[Suggestion] CapabilitiesEnvelope.policy.permission widens
silently** (3271978342). Replaced the inlined string-literal
union with `import type { PermissionPolicy } from
'@qwen-code/acp-bridge'`. Adding a 5th policy upstream would now
trigger a compile error here instead of silently accepting the
narrower set.

**[Suggestion] M=2 unanimity surprise** (3271978356). Default
quorum `floor(M/2)+1` requires unanimity for even M (M=2 →
quorum=2; both voters must agree). An operator picking
`consensus` with two clients expecting "majority of 2 = 1" gets
unanimity instead — a split vote silently hangs until
`permissionTimeoutMs`. Added stderr breadcrumb at issue time
when the default formula yields unanimity (M ≥ 2 and floor(M/2)+1
== M). Mirrors the existing M=0 / cap-applied breadcrumbs added
in Round 5. Formula stays unchanged (true majority for all M is
mutually exclusive with M=1 → quorum=1). Description in the
settings schema also calls out the M=2 case explicitly.

**[Suggestion] Cancel sentinel adversarial test gap**
(3271978359). The existing "resolves cancelled regardless of
policy" test used the originator under designated and a
votersAtIssue voter under consensus — those would be ACCEPTED by
the policies even without the sentinel bypass. Added two
adversarial tests that pin the cross-policy escape hatch:
non-originator voter under designated and not-in-snapshot voter
under consensus.

**[Suggestion] BridgeClient pre-publish collision test gap**
(3271978365). `bridgeClient.requestPermission` throws
`CancelSentinelCollisionError` BEFORE publishing the SSE
`permission_request` to prevent orphan events (the mediator-level
collision check in `mediator.request` happens too late if publish
goes first). Added test asserting the throw + asserting publish
was NOT called + asserting `pendingPermissionIds` was NOT
incremented.

**[Suggestion] Settings descriptions missing security caveats**
(3271978370). Added explicit caveats to `permissionStrategy`
description: (a) `designated` notes that client identity is
self-declared with no proof-of-possession (impersonation by
observing originatorClientId on SSE frames is possible); (b)
`local-only` notes the cancel-sentinel cross-policy escape hatch.
Schema regenerated to `vscode-ide-companion/schemas/settings.schema.json`.

**[Suggestion] Boot validation error class** (3271978374). Replaced
`err.message.includes('invalid policy.')` substring matching with
a dedicated `InvalidPolicyConfigError` class checked via
`instanceof`. A future reworded validation message would have
silently downgraded operator misconfiguration to "fall back to
defaults" under the previous fragile match.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(f3): Round 8 — close legacy clientId oracle + 5 hardening fixes (#4335)

6 follow-up findings from wenshao Round 8 review #4326742064 (state:
COMMENTED — not blocking but addresses leftover risk surfaces).

**[Suggestion] Legacy `respondToPermission` info leak** (3272493777).
Round 7 closed the cross-session client-registration oracle on the
session-scoped vote route, but the legacy workspace-level route
(`POST /permission/<requestId>`) still called
`resolveAnyTrustedClientId` on unknown-requestId paths, throwing
`InvalidClientIdError` (400) for unregistered clientIds and
returning false (404) for registered ones — the same oracle. The
PR #4231 reasoning ("preserve security boundary") was inverted:
the 400-vs-404 distinction WAS the leak. Removed the call,
deleted the now-unused `resolveAnyTrustedClientId` helper, and
updated the previously-leak-asserting test (`rejects unknown
permission votes with unregistered client ids`) to assert the
new uniform `false` behavior across all 3 input shapes
(unregistered / registered / no-clientId).

**[Suggestion] Error-precedence regression test gap +
observability inconsistency** (3272493792). Two parts:
- Added regression test `returns false (not InvalidClientIdError)
  when session exists but requestId is unknown and clientId is
  unregistered` to lock the Round-7 fix against future refactors.
- Promoted the error-precedence guard's stderr line from
  debug-gated `writeServeDebugLine` to unconditional
  `writeStderrLine`, matching the `writeForbiddenStderr` posture
  in the mediator. Operators tailing stderr at 3 AM no longer
  need `QWEN_SERVE_DEBUG=1` to see unexpected 404s on the
  permission endpoint.

**[Suggestion] Settings description "UNANIMITY for even M" was
factually wrong** (3272493795). `floor(M/2)+1` equals M only when
M=2; for M=4 it gives 3 (supermajority), M=6 gives 4 (~67%).
The mediator's own unanimity warning correctly fires only when
M=2. Settings description now reads "UNANIMITY for M=2 (quorum=2,
both must agree) and supermajority for larger even M (M=4 →
quorum=3; M=6 → quorum=4)". VSCode JSON schema regenerated.

**[Suggestion] runQwenServe.ts inline policy unions** (3272493805).
Same drift-protection rationale as the types.ts fix in Round 7.
Imported `PermissionPolicy` from `@qwen-code/acp-bridge`,
replaced 3 inline unions: the `let` declaration, the `as` cast,
and the `VALID_PERMISSION_POLICIES` Set construction. Used a
typed-array + Set<string> pattern (drift caught at array
construction; runtime Set keeps `.has(string)` ergonomics).

**[Suggestion] InvalidPolicyConfigError discrimination needs
positive tests** (3272493818). Extracted the inline
`policyConfig`-validation logic into an exported
`validatePolicyConfig(policyConfig, onWarning?)` helper and
exported `InvalidPolicyConfigError` itself. Added 7 unit tests
covering: empty config, all 4 valid literals, invalid literal
throws (with class identity check + message regex), 4
non-positive-integer quorum cases throw, valid combination
returns, mismatch (consensusQuorum + non-consensus strategy)
emits warning without throwing, no-warning happy path, and
error messages name the failed field. The boot path in
`runQwenServe` now delegates to the helper (one call site,
DRY).

**[Suggestion] Unanimity breadcrumb spammed per-request**
(3272493829). The Round-7 unanimity stderr line fires inside the
synchronous Promise executor of every `request()` call, which
for a 2-client consensus session is EVERY permission request (M=2
unanimity is the normal operating mode, not a rare edge). Added
`unanimityBreadcrumbEmitted` boolean to the mediator class
(per-mediator dedup, parallel to `consensusQuorumCapNoted` on
`MediatorPending`). One emit per daemon lifetime — visible at
boot, silent thereafter. Comment also corrects the "for even M"
generalization to "for M=2" specifically, matching the actual
condition (`floor(M/2)+1 === M` only for M=1 and M=2).

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(f3): Round 9 — terminal-event forbidden cleanup + 7 hardening fixes (#4335)

8 follow-up findings from wenshao Round 9 (4 separate review
records: 4326832742 / 4326833568 / 4326844430 / 4326851074, the
last one a non-blocking comment review). 1 Critical + 7 Suggestions.

**[Critical] Terminal events leaked forbiddenVotes history**
(3272576003). `session_died` / `session_closed` / `client_evicted`
/ `stream_error` reducer cases cleared `pendingPermissions` and
`permissionVoteProgress` but not `forbiddenVotes` /
`forbiddenVoteCount`. Adapters reading view state for a dead
session would render stale rejection data. All 4 cases now
zero out the rejection ring + counter. Parameterized regression
test asserts the cleanup contract.

**[Suggestion] safeAudit JSDoc was orphaned over
writeForbiddenStderr** (3272567323). Two consecutive JSDoc
blocks were stacked back-to-back but the method definitions
followed in the opposite order, so IDE hover and API doc
generation showed `safeAudit`'s docs as `writeForbiddenStderr`'s.
Reordered method definitions so each JSDoc precedes its actual
method.

**[Suggestion] writeForbiddenStderr had no test coverage**
(3272568031). Added a 3-path test (designated / consensus /
local-only) that spies on `process.stderr.write` and asserts each
breadcrumb contains the expected reason fragment plus the
requestId + sessionId for grep-ability. Pins the format so a
future refactor can't silently drop the line.

**[Suggestion] resolveEntry numbered list contradicted code**
(3272581553). The N2-invariant cleanup ladder docstring bundled
"delete from pending + write to resolved" into step 2 ahead of
the SSE emit, but the actual code defers `rememberResolved`
until AFTER `safeEmit` (the I5 inline comment on line 1103
correctly explains this). Split step 2 into two halves around
the emit so the spec faithfully describes the ordering invariant.

**[Suggestion] Dead exports in bridgeClient.ts** (3272581548).
`MAX_RESOLVED_PERMISSION_RECORDS`, `PendingPermission`, and
`PermissionResolutionRecord` were defined and exported but no
longer referenced — the mediator owns the same state under
different names (`permissionMediator.ts:77` / `:319`). The
JSDoc still pointed at deleted closures (`registerPending`,
`resolvedPermissions` map). Removed all three definitions and
the matching re-exports in `cli/src/serve/httpAcpBridge.ts`.

**[Suggestion] detectFromLoopback prefix-match had no direct test**
(3272581557). Supertest in the broader server.test.ts suite
always connects from `127.0.0.1`, so the Round-5 prefix-match
fix for `127.x`-beyond-`.0.0.1`, `::1`, `::ffff:127.*`, and the
fail-closed branches had no coverage. Exported the helper from
`server.ts` (loosened parameter type to a minimal shape so tests
don't need to spin up Express) and added an `it.each` table
covering the variants the fix targets, plus an explicit "does
NOT consult X-Forwarded-For" assertion as a security pin.

**[Suggestion] Validate-policies set is a 4th hardcoded copy**
(3272581563). The policy literals already exist in 3 places —
`PermissionPolicy` type, `SERVE_CAPABILITY_REGISTRY.permission_
mediation.modes`, and `settingsSchema.ts` enum options.
`validatePolicyConfig` now derives its valid-set from
`SERVE_CAPABILITY_REGISTRY.permission_mediation.modes` (single
runtime source of truth). Adding a 5th policy upstream lands in
one place; a future drift between the registry and the type
union would still surface at the `as PermissionPolicy` cast.

**[Suggestion] BridgeClient over-coupled to MultiClientPermissionMediator**
(3272581569). `BridgeClient` only ever calls `mediator.request()`
but its field was typed as the concrete class, forcing every
test stub to fake all 6 mediator members. Narrowed the field type
to `Pick<PermissionMediator, 'request'>` (the frozen interface
from `permission.ts`); the bridge factory still passes the full
`MultiClientPermissionMediator` instance via structural typing.
Test stubs simplified from 6 placeholder members to 1.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(f3): Round 10 — wenshao APPROVED + 3 final polish (#4335)

wenshao APPROVED the PR (review 4327485978: "No issues found in
the latest Round 9 changes... LGTM ✅") with 3 minor follow-up
suggestions in a separate COMMENTED review (4327443147). All
adopted; the 4th suggestion (3273077262) was already addressed
in Round 9.

**[Suggestion] Symmetric stderr breadcrumb on legacy
respondToPermission** (3273077256). The session-scoped sibling
already writes an unconditional `writeStderrLine` on its
`actualSessionId === undefined` rejection path (Round 8 /
3272493792); the legacy `POST /permission/<id>` route returned
`false` silently after the Round-8 oracle removal, leaving an
observability gap. Added matching `writeStderrLine`. Operators
tailing stderr at 3 AM now see legacy-route 404s without needing
QWEN_SERVE_DEBUG=1.

**[Suggestion] consensusQuorum contract mismatch** (3273077270).
The warning text told the operator "the override will be
ignored" but the function still propagated `permissionConsensusQuorum`
to BridgeOptions. The downstream mediator only reads it under
the consensus policy, so behavior was correct — but the public
contract contradicted itself. Adopt option (a): drop the value
to `undefined` when the strategy is not 'consensus' so the
returned struct matches what the warning promises. Updated the
existing `validatePolicyConfig` test to assert the new contract.

**[Suggestion] Stderr-breadcrumb assertion missing from
error-precedence regression test** (3273077272). The Round-8
test pinned the return-value behavior (`false`) but not the
unconditional-stderr promotion that was the primary behavioral
change of that hunk. Added `vi.spyOn(process.stderr, 'write')`
+ assertions for both "rejected permission vote" and the literal
requestId in the test. A future refactor that drops or downgrades
the log line is now caught.

**[Suggestion] _validPolicies underscore-prefix misleading**
(3273077262 — already addressed). Round 9's commit 6793b89
replaced the literal `_validPolicies` array with a single Set
derived from `SERVE_CAPABILITY_REGISTRY.permission_mediation.modes`
(per separate suggestion 3272581563). The underscore-prefixed
identifier is gone in current HEAD; replied via PR comment
pointing wenshao at the existing fix.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

…amp / provenance / errorKind / state_resync_required) (#4360)

* feat(serve): stamp serverTimestamp / tool provenance / errorKind on daemon events (#4175 F4 prereq)

Adopts chiga0's three P0 SDK-side blockers from #4175 comment #19 —
the SDK side already consumes these fields (PR #4353), but daemon
hadn't stamped them yet, leaving the corresponding UI affordances
inert. All three stampings are purely additive on the wire and don't
require any SDK type changes (SDK already has forward-compat field
slots).

**#19.1 — `_meta.serverTimestamp` on every SSE frame** (`server.ts`
`formatSseFrame()`)

Stamped at the SSE write boundary (NOT EventBus.publish) so the
in-memory `BridgeEvent` type stays unchanged and internal consumers
don't see `_meta`. Pre-existing `_meta` keys (e.g. tool_call's
`_meta.toolName`) are preserved via spread merge. SDK reads via the
3-location probe in `extractServerTimestamp` (chiga0's PR #4353);
we pick `_meta.serverTimestamp` (Anthropic convention) so top-level
event type stays unpolluted.

Why this matters: pre-fix, multi-client UIs showing "X minutes ago"
or sorting transcript blocks by emit time used each client's local
clock — drifts of tens of seconds to minutes across browsers/tabs/
mobile produced visibly inconsistent timestamps.

**#19.2 — `tool_call` `provenance` + `serverId` on every emitter
event** (`ToolCallEmitter.ts`)

New static `ToolCallEmitter.resolveToolProvenance(toolName,
subagentMeta)` returns `{ provenance: 'builtin' | 'mcp' | 'subagent';
serverId? }`. Resolution rules (per user-confirmed design decision
from issue comment): subagent takes precedence (set when
subagentMeta is present); `mcp__<server>__<tool>` naming heuristic
classifies MCP tools with serverId; everything else is builtin.

Stamped on `emitStart` AND `emitResult` AND `emitError` (all three
emit paths) so a reconnecting client receiving a `tool_call_update`
frame from the replay ring (without the original `tool_call` start
event) can still derive the provenance. Provenance is stable per
tool, so stamping on every event is redundant — but the marginal
serialization cost is tiny and reconnect correctness wins.

Chose the naming heuristic (not ToolRegistry lookup) per user
confirmation: matches the SDK's own fallback (chiga0 PR #4353), no
new ctx-dep on emit hot path, no signature changes.

**#19.3 — `errorKind` on `stream_error`** (`server.ts` line ~1955)

Stamped via `mapDomainErrorToErrorKind(err)` — the 7-value classifier
already lives in `@qwen-code/acp-bridge/status.ts` since #4319. When
the classifier returns `undefined` (generic Error etc.) the field is
omitted — strictly additive. SDK consumers handle "errorKind absent"
as before (fall back to rendering `error` text).

NOT stamped on `session_died` because the 3 emit sites in `acp-bridge/
bridge.ts` don't have a classifiable `err` in scope:
- `channel_closed` carries only exitCode/signalCode (no error)
- `killed` is user-initiated (no domain error)
- `daemon_shutdown` is operator-initiated (no domain error)

A follow-up could thread channel-spawn errors through to the
session_died emit site to enable `errorKind: 'init_timeout'` /
`missing_binary` classification — left for a separate PR to avoid
mixing protocol stamping with lifecycle plumbing.

Verification
- `npx vitest run packages/cli/src/serve/server.test.ts -t "serverTimestamp|stream_error|errorKind"` — 5 pass
- `npx vitest run packages/cli/src/acp-integration/session/emitters/ToolCallEmitter.test.ts` — 46 pass (+ 11 new tests for resolveToolProvenance + provenance stamping on all 3 emit paths)
- `npx vitest run packages/cli/src/acp-integration/session/HistoryReplayer.test.ts` — 17 pass
- TypeScript clean on touched regions; pre-existing F3 (#4335 merge) errors elsewhere are unrelated.

Existing test updates
- 15 `_meta: { toolName: 'X' }` assertions in ToolCallEmitter.test.ts updated to include `provenance: 'builtin'` (defensive — catches accidental drift if a future refactor stops stamping). 2 strict-equality assertions in HistoryReplayer.test.ts similarly updated. The first SSE-frame test in server.test.ts switched from `toEqual` to `toMatchObject` since `_meta.serverTimestamp` makes exact equality brittle; a dedicated test pins the new field's shape.

* feat(serve+sdk): detect SSE ring eviction on resume, expose state_resync_required (#4175 F4 prereq)

Closes the multi-client SSE reducer divergence bug Ilya0527 raised in
#4175 comment #15. Pre-fix scenario:

1. Consumer's SSE stream drops; client buffers `Last-Event-ID: N`.
2. Network reconnects long enough later that events `[N+1, ringHead-1]`
   were evicted from the daemon's per-session ring.
3. Daemon's `subscribe({lastEventId: N})` silently replays only the
   surviving suffix.
4. Consumer's SDK reducer keeps applying deltas as if the stream was
   contiguous. Its state has now drifted from the daemon's truth —
   no terminal signal, no warning. The `SessionState` reducer's
   "same event stream in → same state out" purity guarantee is
   broken.

The bug's blast radius is exactly when multi-client matters: F4
brings up the TUI / IDE / web client adapters that share session
state, so divergence becomes visibly inconsistent across clients.

**Daemon side** (`packages/acp-bridge/src/eventBus.ts`)

In `subscribe()`'s replay path, detect ring eviction by comparing
the ring's earliest id against `lastEventId + 1`. When a gap exists,
force-push a synthetic terminal `state_resync_required` frame BEFORE
the surviving replay events:

```
{ v: 1, type: 'state_resync_required',
  data: { reason: 'ring_evicted',
          lastDeliveredId: N,
          earliestAvailableId: M } }
```

Per user-confirmed design (issue comment discussion): the frame has
NO `id` (mirrors the `client_evicted` synthetic terminal pattern so
it doesn't burn a slot in the per-session monotonic sequence). Replay
continues after the resync frame — the SDK reducer auto-skips
subsequent deltas (see below) but the frames stay on the wire so
adapters have the option to compute a "what you missed" diff later.

**SDK side** (`packages/sdk-typescript/src/daemon/events.ts`)

Adds:
- `'state_resync_required'` to `DAEMON_EVENT_TYPES` union
- `DaemonStateResyncRequiredData` + `DaemonStateResyncRequiredEvent`
- `isStateResyncRequiredData` predicate
- `DaemonStreamLifecycleEvent` union widened
- Reducer state fields: `awaitingResync: boolean`,
  `resyncRequiredCount: number`, `lastResyncRequired?`
- Reducer case for `state_resync_required` — sets the flag, increments
  count, records data
- **Top-of-reducer gate**: when `awaitingResync === true`, all non-
  terminal events are auto-skipped (still advance `lastEventId`).
  Terminal lifecycle events (`session_died` / `session_closed` /
  `client_evicted` / `stream_error`) STILL apply — critical end-of-
  stream signals don't depend on prior state being current.
- Re-exported `DaemonStateResyncRequiredData` / Event from
  `daemon/index.ts` and `src/index.ts` (matches surface posture of
  sibling lifecycle types).

Consumer recovery contract: when `state.awaitingResync === true`,
call `loadSession` (out of band) to fetch the daemon's canonical
session snapshot, then reconstruct view state via
`createDaemonSessionViewState({...seed from loaded state})`. The
fresh state defaults `awaitingResync: false` so the seed implicitly
clears the flag.

**Side fix** (`stream_error` errorKind)

`DaemonStreamErrorData.errorKind?: string` typed for the optional
classification field that Commit 1 (`14637cd79`) added daemon-side.
Strictly additive — old daemons omit the field, SDK falls back to
rendering `error` text.

Verification
- `packages/acp-bridge`: 6 files, 108/108 pass (+5 new resync-detection
  tests; 1 existing "default ring size 8000" test updated to acknowledge
  the synthetic resync frame at the head of its replay batch).
- `packages/sdk-typescript`: 13 files, 451/451 pass (+8 new reducer
  resync tests covering set/skip/terminal-passthrough/recovery/
  repeated-resync/malformed-payload).
- TypeScript clean across both packages on touched regions.

* fix(acp-bridge): preserve FsError structure over ACP wire (#4360 Codex round 2 fold-in)

Adopts Codex review round 2 P2 finding on PR #4360 — fold-in to the
F4 prereq scope per user's "a" decision.

**Problem**: When the `BridgeFileSystem` adapter (introduced in
#4334 fs adapter wiring) throws a structured `FsError` (e.g.
`kind: 'untrusted_workspace'` / `kind: 'symlink_escape'` / `kind:
'file_too_large'`), the `@agentclientprotocol/sdk` default RPC
error serialization only sends `error.message` as JSON-RPC -32603
"Internal error". The structured `kind` / `status` / `hint` fields
on FsError are stripped on the way to the agent.

Downstream impact: SDK consumers receiving the ACP error payload
lose the typed discriminator and have to regex-match the human-
readable message to dispatch UI (auth retry vs file picker vs
proxy hint). This silently regresses what the FsError-typed
contract was supposed to provide.

**Fix**: At the bridge boundary (`BridgeClient.writeTextFile` and
`BridgeClient.readTextFile`), catch errors from `this.fileSystem.
writeText/readText` calls. Duck-type check for FsError shape
(`err.name === 'FsError'` + `typeof err.kind === 'string'`); when
matched, rethrow as ACP `RequestError(-32603, message, {errorKind,
hint, status})`. The agent's RPC client now receives `data.
errorKind` and can branch on the closed-enum kind.

Cross-package note: FsError lives in `cli/src/serve/fs/errors.ts`
and acp-bridge can't `import { FsError }` from cli (dependency
inversion). Same duck-typing pattern that `mapDomainErrorToErrorKind`
(status.ts) already applies to `TrustGateError` / `SkillError` for
the same cross-package bundling reason — `instanceof` would fail
across package boundaries when bundlers don't dedupe.

**Code shape**

```typescript
function isFsErrorShape(err: unknown): err is FsErrorShape {
  return (
    err instanceof Error &&
    err.name === 'FsError' &&
    typeof (err as { kind?: unknown }).kind === 'string'
  );
}

function preserveFsErrorOverAcp(err: unknown): never {
  if (isFsErrorShape(err)) {
    throw new RequestError(-32603, err.message, {
      errorKind: err.kind,
      ...(err.hint !== undefined ? { hint: err.hint } : {}),
      ...(err.status !== undefined ? { status: err.status } : {}),
    });
  }
  throw err;
}
```

Applied at both `if (this.fileSystem) { ... }` blocks (writeTextFile
+ readTextFile) — wrapped the adapter call in try/catch +
`preserveFsErrorOverAcp(err)`. Non-FsError errors are rethrown
unchanged (default ACP serialization is fine for unstructured
errors; only the structured shape needs preservation).

JSON-RPC code stays at -32603 (internal error) rather than mapping
FsError.kind → JSON-RPC code. Rationale: the JSON-RPC standard
defines only a handful of code values (-32700/-32600/-32601/-32602/
-32603 + a reserved range for application errors), and mapping
~10 FsError kinds to that narrow space is lossy. Instead the
structured `data.errorKind` carries the semantic information SDK
consumers need; JSON-RPC code remains the generic "an error happened"
signal.

**Tests** (+5 in `bridgeClient.test.ts`)

- writeTextFile FsError → ACP RequestError with errorKind in data
- readTextFile FsError preserving symlink_escape kind (no hint
  field present → not stamped, spread guard works)
- non-FsError pass-through (plain Error stays plain Error, no
  RequestError wrap)
- hint field preservation when present
- defensive: error with `kind` field but wrong `name` does NOT get
  wrapped (e.g. PermissionForbiddenError happens to have a kind
  field internally — must NOT be confused for FsError)

Verification: 113/113 acp-bridge tests pass (+5 new FsError-
preservation tests). Full serve suite shows pre-existing F3-related
failures unrelated to this change (verified in isolation).

* fix: 7 wenshao/copilot review fold-ins on #4360 (1 Critical + 6 Suggestion)

Adopts all 7 review threads from the first wenshao + Copilot review
round on PR #4360. All technical fixes (no judgment calls).

**[Critical] BridgeTimeoutError constructor blocks tsc** (wenshao
PRRT_kwDOPB-92c6DfcRI)

`server.test.ts:4670` called `new BridgeTimeoutError('initialize
timed out')` but the constructor signature is `(label: string,
timeoutMs: number)` — TS2554 blocked `tsc --noEmit` and `npm run
build`. Fixed to `new BridgeTimeoutError('initialize', 5000)` per
suggested fix; resulting message `"HttpAcpBridge initialize timed
out after 5000ms"` still satisfies the existing
`.toContain('timed out')` assertion.

**[Suggestion] Copilot JSDoc package name** (Copilot
PRRT_kwDOPB-92c6De-Sm, ToolCallEmitter.ts:210)

JSDoc referenced `@qwen-code/core/mcp-tool` but the actual package
is `@qwen-code/qwen-code-core` with the file at
`packages/core/src/tools/mcp-tool.ts`. Updated the reference.

**[Suggestion] Copilot errorKind type widening** (Copilot
PRRT_kwDOPB-92c6De-Ro, events.ts:244)

`DaemonStreamErrorData.errorKind` was typed as `string` and the
JSDoc said "7-value" closed enum — but `DAEMON_ERROR_KINDS` actually
has 8 values, and `SERVE_ERROR_KINDS` (daemon-side) has 9 (adds
`stat_failed`). Typed as `DaemonErrorKind | (string & {})` for
forward-compat: SDK consumers get IDE autocomplete on the known 8
kinds while still accepting future daemon-side additions (like
`stat_failed`) without a type error. Updated JSDoc to accurately
list 8 current values + call out the forward-compat widening.

Side observation (NOT in scope of this PR): `DAEMON_ERROR_KINDS`
(SDK) lacks `stat_failed` that exists in `SERVE_ERROR_KINDS`
(daemon). That's a separate drift fix.

**[Suggestion] TERMINAL wording misleading** (wenshao
PRRT_kwDOPB-92c6Dj-JL, eventBus.ts:369)

Comment called `state_resync_required` a "TERMINAL synthetic frame"
but it's emitted FIRST (before replay) and the stream stays OPEN.
Genuine terminals like `client_evicted` close the stream after the
frame. Rewrote the comment per suggestion: "id-less synthetic
frame... Unlike `client_evicted`, the stream stays OPEN" — so an
oncall reading the source at 3am gets the right mental model.

**[Suggestion] `_meta` merge dead code + stale reference** (wenshao
PRRT_kwDOPB-92c6Dj-JF, server.ts:2569)

The `existingMeta` merge reads `event._meta` at BridgeEvent top
level, but ToolCallEmitter's `_meta` lives nested inside
`event.data._meta` (publish path goes through `events.publish({type:
'session_update', data: params})`). In production `existingMeta` is
always undefined — the merge is a forward-compat escape hatch, not
an active merge. Also the comment referenced
`extractServerTimestamp` (sdk-typescript) which grep confirms
doesn't exist yet (it's planned in chiga0 PR #4353).

Rewrote the comment block to (1) acknowledge no current producer
sets `_meta` at the top level — it's a forward-compat hook for
future envelope-level metadata; (2) drop the stale
`extractServerTimestamp` reference and instead note that chiga0
PR #4353 plans the 3-location probe. Code shape unchanged
(forward-compat spread stays).

**[Suggestion] session_closed + client_evicted passthrough tests**
(wenshao PRRT_kwDOPB-92c6Dj-JW, daemonEvents.test.ts:2284)

`RESYNC_PASSTHROUGH_TYPES` has 5 members but only `session_died`
and `stream_error` had passthrough tests. Added two missing tests:
`session_closed` and `client_evicted` while awaitingResync.
Critical because if a future refactor accidentally drops either
from the set, a consumer in resync limbo would silently swallow
the terminal signal and the UI would hang on "loading resync
state…".

**[Suggestion] readTextFile non-FsError passthrough test** (wenshao
PRRT_kwDOPB-92c6Dj-JX, bridgeClient.test.ts:251)

The non-FsError pass-through test only covered `writeTextFile`.
Added a symmetric `readTextFile` test — the two `try/catch` blocks
in `bridgeClient.ts` are independent, so test parity guards against
divergent refactors (e.g. someone adding wrapping on one side but
not the other).

Verification
- `packages/acp-bridge`: 6 files, 114/114 pass (+1 new readTextFile
  non-FsError test).
- `packages/sdk-typescript`: 75/75 pass on daemonEvents.test.ts
  (+2 new session_closed / client_evicted passthrough tests).
- `packages/cli/src/serve/server.test.ts`: 248 tests pass on
  touched cases (5 SSE / serverTimestamp / stream_error tests).
  Pre-existing F3 (#4335 merge) test failures unrelated to this
  PR's changes — verified by stash-test-restore on clean tree.
- TypeScript clean on touched regions; `BridgeTimeoutError`
  2-arg fix unblocks `tsc --noEmit` for the test file.

* fix: 3 wenshao observability fold-ins on #4360 (all Suggestion)

Adopts all 3 threads from wenshao's second review round on PR #4360.
All Suggestion-level — daemon-side observability + 1 missing SDK
reducer test.

**[Suggestion] SSE ring eviction silently emits state_resync_required**
(PRRT_kwDOPB-92c6Dp_Uk, eventBus.ts:394)

Pre-fix: when a consumer reconnects past the ring boundary, the
daemon emits `state_resync_required` with zero stderr breadcrumb.
A 3am oncall chasing "my UI is frozen with stale state" couldn't
grep daemon logs to distinguish (a) ring undersized, (b) client
reconnecting too slowly, (c) network partition causing repeated
reconnects.

Fix: detect `next.value.type === 'state_resync_required'` in the
SSE handler's iter loop in `server.ts` and emit a `writeStderrLine`
with the gap details (`lastEventId`, `earliestInRing`, computed
`gap` count, `reason`). Logged at the route boundary rather than
inside `EventBus.subscribe` to keep the bus implementation pure +
concentrate daemon-side observability in the route handler that
already logs socket errors + heartbeats.

**[Suggestion] Bridge iterator throw forwarded to client but not
logged daemon-side** (PRRT_kwDOPB-92c6Dp_Uo, server.ts:1956)

Pre-fix inconsistency: the adjacent `res.on('error', ...)` handler
at line ~1925 logs SSE socket errors with `writeStderrLine`, but
the bridge-iterator-catch block at line ~1940-1965 sends a
`stream_error` SSE frame to the client AND swallows the error
daemon-side. When the bridge iterator throws (subprocess crash,
channel protocol error, unhandled rejection), distinguishing
"subprocess OOM-killed" from "protocol bug" required attaching a
debugger.

Fix: mirror the adjacent handler's pattern — add `writeStderrLine`
before the `stream_error` SSE frame send, including the classified
`errorKind` (when available) in brackets so operators can grep for
`[init_timeout]` / `[missing_binary]` etc.

**[Suggestion] No SDK reducer test verifying stream_error.errorKind
flowthrough** (PRRT_kwDOPB-92c6Dp_Uq, daemonEvents.test.ts:2331)

The daemon-side wire format is tested in `server.test.ts`
(`parsed.data.errorKind === 'init_timeout'`) and
`DaemonStreamErrorData` now declares `errorKind?`, but the SDK
reducer test suite never fed a `stream_error` event with
`errorKind` and asserted `state.streamError?.errorKind`. A future
refactor stripping `errorKind` from the reducer's data assignment
(e.g. spreading only `{error}`) would silently regress without
test signal.

Fix: added `captures errorKind on stream_error in view state` test
exercising the full pipeline — reducer receives stream_error with
errorKind, view state's `streamError.errorKind` matches.

Verification
- `packages/sdk-typescript`: 76/76 daemonEvents tests pass (+1
  new flowthrough test).
- `packages/cli/src/serve/server.test.ts`: 6 targeted serverTimestamp
  / stream_error / errorKind tests pass — server.ts changes are
  observability-only (no behavior change to wire format).
- Pre-existing F3 (#4335 merge) test failures elsewhere are
  unrelated to this PR's changes.

* test(serve): 2 wenshao observability fold-ins on #4360 (stderr log coverage)

Adopts both threads from wenshao's third review round on PR #4360.
Both Suggestion-level — pin the daemon-side stderr log artifacts that
commit `dce2fed0f` introduced. Pre-fix: the EventBus-level
state_resync_required emission was tested in eventBus.test.ts, and
the SSE wire shape was tested in server.test.ts, but the actual
operator-facing artifacts (the stderr log lines themselves) had no
test coverage. A regression swapping operands in the `gap`
arithmetic, dropping the sessionId from the log, or breaking the
`[errorKind]` suffix would ship silently and only surface when an
operator went grepping during an incident.

**[Suggestion] SSE ring eviction stderr log untested**
(PRRT_kwDOPB-92c6Dqtlb, server.ts:1948)

Added 2 tests:
- `writes a daemon-side stderr log on SSE ring eviction` — yields
  a `state_resync_required` frame from a fake bridge, spies on
  `process.stderr.write`, asserts the captured log contains
  `session sess-A` + `lastEventId=5` + `earliestInRing=12` +
  `gap=6 events` (pins the arithmetic) + `reason=ring_evicted` +
  `loadSession` (the recovery hint).
- `falls back to "?" placeholders when state_resync_required data is
  partial` — yields a frame with empty `data: {}`, asserts every
  `?? '?'` branch fires (lastEventId=? / earliestInRing=? /
  gap=? events / reason=?). Defensive against future daemon schema
  changes that drop one of these fields.

**[Suggestion] Bridge iterator error stderr log untested**
(PRRT_kwDOPB-92c6Dqtlh, server.ts:1993)

Added 2 tests:
- `writes a daemon-side stderr log on bridge iterator error` — fake
  bridge throws plain `Error('agent died')` mid-stream, captures
  stderr, asserts the log contains `session sess-A` + `agent died`,
  and **no** `[…]` suffix (plain Error → `mapDomainErrorToErrorKind`
  returns undefined → no suffix).
- `includes [errorKind] suffix in bridge iterator error log when
  classified` — fake bridge throws `BridgeTimeoutError('initialize',
  5000)`, asserts the log contains `[init_timeout]`. Pins the
  classified-vs-unclassified branch of the conditional suffix
  template.

All 4 tests use `vi.spyOn(process.stderr, 'write').mockReturnValue(
true)` + filter `mock.calls` for the relevant log prefix — same
pattern as the existing `mcp-client-manager.test.ts` stderr-spy
tests in core, plus `startupProfiler.test.ts` in cli.

Verification: 7/7 targeted observability tests pass. Pre-existing
F3 (#4335 merge) test failures elsewhere are unrelated to this
PR's changes.

* fix(serve): post-merge fixes for #4291 review (7 threads) (#4305)

* fix(serve): address qwen-latest review on merged #4291 (7 threads)

Seven post-merge findings from the qwen-latest review on #4291,
all real. Most are tightening fixes for issues introduced by the
earlier rounds of #4291 — the same security / DRY / observability
classes the original review surfaced, applied to surfaces that
weren't covered initially.

#1 (deviceFlow.ts:1179) — late-poll observer closure retained the
entire entry by reference (deviceCode/pkceVerifier BrandedSecrets +
cancelController) for the lifetime of the daemon if `provider.poll()`
never settled. Memory leak + indefinite secret retention. Destructure
the four fields the closure actually needs (deviceFlowId, providerId,
initiatorClientId, audit sink) so the entry is GC-eligible the
moment runPollTick returns.

#2 (server.ts) — `callerIsInitiator` was duplicated verbatim across
three locations: GET handler, toDeviceFlowStartResponseBody,
toDeviceFlowStateBody. The exact bug class #4291 was fixing was
"POST and GET diverged on the same redaction policy" — duplicating
the gate recreated the preconditions for divergence. Extracted to
shared `callerIsDeviceFlowInitiator(view, callerClientId)` helper
with the consolidated threat-model JSDoc. All three sites now call
the helper.

#3 (deviceFlow.ts:1110) — timeout callback constructed two separate
`DeviceFlowPollTimeoutError` instances (one for `signal.reason`, one
for the wrapper rejection). Each capture its own V8 stack trace,
and `signal.reason.stack` would diverge from the caught rejection's
stack — confusing for operators inspecting both. Build the sentinel
ONCE per timer fire and pass the same instance to both sites.

#4 (qwenDeviceFlowProvider.ts:273) — `Error.name` is a freely
assignable string property; a hostile fetch wrapper could set
`e.name = 'X\n[serve] FAKE LINE\x1b[31m'` to inject log lines or
ANSI sequences via the same vector we already closed for `oauthError`.
The non-OAuth catch path interpolated `${err.name}` raw. Apply the
same `sanitizeForStderr()` helper.

#5 (deviceFlow.ts:1551) — on the timeout path, `rawProviderError`
is undefined (deliberately, to skip the misleading
`provider.poll() threw (raw): ...` audit template), but that left
the audit hint field omitted entirely. Operators reading the
durable audit trail saw `errorKind: 'upstream_error'` with no signal
whether it was a hung IdP or a generic provider failure. Use
`result.hint` (which already carries the timeout-specific
`provider.poll() timed out after Nms; check IdP connectivity` text
built in the catch) so the audit matches the SSE event.

#6 (server.ts) — the `QWEN_SERVE_DEBUG` env-var check was inlined
in the GET route handler, duplicating the `isServeDebugMode()`
helper from `./debugMode.js` that workspaceAgents and
workspaceMemory already use. The inline copy also had a dead `?? ''`
fallback (the value is guaranteed truthy at that point per the
preceding check). Use the canonical helper.

#7 (deviceFlow.ts:1217) — late-rejection observer interpolated the
raw `lateErr.message` into the audit hint (truncated to 256 bytes,
but RFC 8628 `device_code` values fit comfortably in 256 bytes).
The provider's catch already uses the `name + length` redaction
pattern to prevent WAF-echoed `device_code`/PKCE leaks; the
registry layer was undoing that hardening because the same failure
settled late. Apply the same `name + length` pattern at the late-
rejection site.

Tests:
- Existing late-rejection test reseeded with a `device-code-secret-*`
  substring inside the long detail; hard-negative-asserts the seeded
  secret is absent from the audit + asserts the new
  `Error (message N bytes; raw suppressed)` shape.
- Existing poll-timeout test now also asserts: hint IS defined on
  the audit (not omitted), hint contains `'timed out after'` /
  `'check IdP connectivity'`, and `signal.reason instanceof
  DeviceFlowPollTimeoutError` (proves the single sentinel is
  shared between abort and reject).
- New `sanitizes control characters in attacker-controlled
  err.name` test in qwenDeviceFlowProvider.test.ts pins the round-4
  #4 fix with a hostile `e.name` containing `\n` + `\x1b[31m...`.

cli serve 702/702 (was 686, +16 — additional tests imported via
the acp-bridge package lift on main); sdk 421/421; typecheck clean
across all 4 workspaces; eslint --max-warnings 0 clean on touched
files.

Refs: #4175, #4255, #4291

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): address deepseek-v4-pro review on #4305 (4 threads)

Round-5 fold-in. Four findings from the deepseek-v4-pro review on
PR #4305 — all real, three are sister fixes for the same security
classes that #4305 already closed at adjacent surfaces.

#1 (deviceFlow.ts) — `pollTimedOut` race correctness. The flag was
set unconditionally inside the timer callback. If the provider
settled the wrapper at 29.9s, `finally` would call
`clearScheduled(pollTimer)` — but if the timer callback was already
queued for execution before the clear landed (a real possibility
in Node's event-loop ordering, even if not always observed in
practice), this branch could still run and incorrectly mark
`pollTimedOut`. Move the flag assignment to the catch block where
the settled cause is unambiguous via `instanceof
DeviceFlowPollTimeoutError`. New test pins the negative: provider
beats the timeout → no spurious `lost_late_poll_after_timeout`
audit even after ticking 2× the ceiling.

#2 (deviceFlow.ts) — late-rejection observer interpolated raw
`lateErr.name` into the audit hint without sanitization. Same
attacker-controlled vector closed at the provider layer for
`err.name` in round-4. Route through `sanitizeForStderr`.

#3 (deviceFlow.ts) — late-success observer interpolated
`latePollResult.kind` directly into the audit template. While the
typed shape is `'pending' | 'slow_down' | 'success' | 'error'`, a
non-conforming provider could return an arbitrary string. Same
log-injection vector. Route through `sanitizeForStderr`.

#4 (qwenDeviceFlowProvider.ts → deviceFlow.ts) —
`sanitizeForStderr` only stripped ASCII C0/C1 + DEL; bypass via
Unicode lookalikes:
  - U+2028/U+2029: LINE/PARAGRAPH SEPARATOR (newline-equivalent in
    most Unicode-aware terminals — most direct log-forging vector)
  - U+200B–U+200F: zero-width chars + LRM/RLM
  - U+202A–U+202E: bidirectional override controls
  - U+FEFF: BOM / ZWNBSP

A malicious IdP returning `slow_down
[serve] FAKE` in
`oauthError` would otherwise still forge log lines.

Architectural change: `sanitizeForStderr` was previously private to
`qwenDeviceFlowProvider.ts`. To address #2/#3, the registry layer
needs to call it too. Lifted into `deviceFlow.ts` (the foundation
module) and re-imported from the provider. Single source of truth;
the regex is now a module-level constant compiled once with explicit
`\uXXXX` escapes (via `String.raw` so the source is greppable, not
literal-Unicode-laden).

Tests:
- `does NOT attach late-poll observer when the provider beats the
  timeout` — N1 race regression
- `sanitizes hostile latePollResult.kind in late-observer audit` — N3
- `sanitizes hostile lateErr.name in late-rejection observer audit` — N2
- `sanitizes Unicode lookalike controls (U+2028 LINE SEPARATOR,
  bidi, ZWNBSP) in oauthError` — N4

cli serve 706/706 (was 702, +4 — all new round-5 tests); sdk
421/421; typecheck clean; eslint --max-warnings 0 clean on touched
files.

Refs: #4175, #4255, #4291, #4305

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): address gpt-5.5 + qwen-latest review on #4305 round-5 (5 threads)

Round-6 fold-in. Five findings split between maintainability,
security hardening, and a real defensive bug.

#1 (qwenDeviceFlowProvider.test.ts) — gpt-5.5: round-5 #4 test
embedded U+2028 / U+200E / U+FEFF as literal characters in source.
Invisible in GitHub diffs / most editors; the negative
`not.toContain('')` looked like an empty-string check. Rewrote
the payload + assertions to use named `\uXXXX`-bound constants.
Also added a companion test exercising U+2066–U+2069 (round-6 #5
below).

#2 (deviceFlow.ts) — qwen-latest: the late-poll observer's
`void tracked.then(...)` was missing a terminal `.catch(() => {})`.
A synchronous throw inside either handler (e.g., a misbehaving
`audit.record`: backpressure, malformed payload, sink out-of-disk)
would reject the derived promise unhandled. On Node 22's default
`--unhandled-rejections=throw`, that crashes the daemon. Added the
terminal `.catch(() => {})` matching the persist-tracker pattern.
New test injects a poison audit sink that throws specifically on
the `lost_late_poll_after_timeout` call; asserts `flushAsync()`
resolves cleanly.

#3 (deviceFlow.ts) — qwen-latest: the `case 'error'` audit-record
hint interpolated `rawProviderError` (raw `err.message`) without
`sanitizeForStderr`. Per ES2019+ `JSON.stringify` no longer escapes
U+2028/U+2029 — those would still forge log lines downstream
through file/stdout audit sinks. Apply the same sanitizer used on
every other provider-controlled audit path. New test pins a hostile
provider message containing U+2028 + ANSI escape and asserts
neither survives.

#4 (deviceFlow.ts) — qwen-latest: the round-5 #1 comment claimed
"`DeviceFlowPollTimeoutError` isn't exported as a public DeviceFlow
contract", but it IS `export class` (the test file constructs it
directly for fixtures). With `pollTimedOut = true` keyed solely on
`instanceof`, a future provider that imports + throws the class
would spoof the registry's "I caused the timeout" signal —
attaching a phantom late-poll observer.

Fix: introduce a runtime brand `_isRegistryTimeout: boolean` on the
class (default `false`) plus an internal-only
`makeRegistryPollTimeoutError(ms)` helper that sets the brand to
`true`. The brand is set ONLY at the registry's race-timer
construction site. Both gates updated:
  - `if (err instanceof X && err._isRegistryTimeout === true)` in
    the catch (for `pollTimedOut`)
  - `if (lateErr instanceof X && lateErr._isRegistryTimeout === true)`
    in the late-rejection self-filter

A provider-thrown brand-false instance now flows through the
generic provider-throw audit path — correctly auditing the misuse
rather than silently swallowing it. Repurposed the original "no
double-audit when registry's own DeviceFlowPollTimeoutError is
late-rejected" test (which was actually exercising the brand-false
path) into the inverted assertion: brand-false provider throw IS
audited as a real failure. Removed the orphaned old assertion; the
brand-true happy path is implicitly covered by the hanging-provider
test (which exercises the registry-built timeout end-to-end).

#5 (deviceFlow.ts) — qwen-latest: `sanitizeForStderr` regex covered
U+202A–U+202E (bidi embedding/override) but missed U+2066–U+2069
(LRI/RLI/FSI/PDI). These are the primary CVE-2021-42574
("Trojan Source") attack vectors — a hostile IdP swapping U+2066
for U+202D achieves the same visual reordering and would have
bypassed the round-5 filter entirely. Extended the regex range and
JSDoc; new test exercises U+2066/U+2068/U+2069 in `oauthError` and
asserts none survive while substantive ASCII parts remain.

cli serve 713/713 (was 710, +3 round-6 tests + the round-5 #4
rewrite + the round-6 #5 companion); typecheck clean across all 4
workspaces; eslint --max-warnings 0 clean on touched files.

Refs: #4175, #4255, #4291, #4305

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): replace literal U+2028 with explicit 
 escape in round-6 #3 test

PR #4312 review (Copilot): the round-6 #3 test (sanitizes
rawProviderError) regressed back to embedding a literal U+2028
character in source via `const U_2028 = ' '`. That's the same
maintainability anti-pattern round-6 #1 was fixing in the sister
test. Internal-consistency fix: switch to the explicit `
`
escape so the constant is greppable and reviewable in GitHub diffs.

Refs: #4291, #4305, #4312

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): post-merge P2 corrections from Codex review on #4282 (#4297)

* fix(serve): post-merge P2 corrections from Codex review on #4282

Follow-up to PR #4282 (Wave 4 PR 17) addressing four P2 issues
flagged by Codex's `/review` after the squash-merge to main:

P2-1 — Read the workspace context filename for init
  `qwen serve` parent never goes through `loadCliConfig`, so the
  process-global `getCurrentGeminiMdFilename()` stays on the default
  `QWEN.md` even when the workspace configures
  `context.fileName: 'AGENTS.md'`. `runQwenServe` now snapshots the
  workspace's merged setting at boot and forwards via
  `BridgeOptions.contextFilename`, so init writes the same file the
  ACP child reads.

P2-2 — Restart MCP servers with a fresh disabledTools snapshot
  `Config.disabledTools` was frozen at construction time;
  `setWorkspaceToolEnabled` only updated settings.json. The
  documented "toggle + restart" workflow re-registered just-disabled
  tools because rediscovery still saw the bootstrap snapshot. Added
  `Config.setDisabledTools()` plus a re-read at the ACP restart
  handler so `discoverMcpToolsForServer` honors the latest set.

P2-3 — Match the SDK timeout to the daemon's restart budget
  Bridge waits up to 300s for stdio MCP discovery; SDK helper used
  the client-wide 30s default and aborted valid slow restarts.
  Added a per-call `timeoutMs` plumbed through `fetchWithTimeout`,
  defaulting `restartMcpServer` to 5 minutes.

P2-4 — Reject symlinked parent directories before init writes
  `lstat(target)` only checked the final component; a symlinked
  parent (e.g. `docs -> /tmp` with `context.fileName:
  'docs/QWEN.md'`) would let `writeFile` follow the link and create
  / truncate outside `boundWorkspace`. Added
  `canonicalizeExistingAncestor` (walks up through ENOENT to the
  deepest extant ancestor, then `realpath`s) and verifies the
  canonical parent stays within the canonical workspace.

5 new tests (4 bridge / 2 SDK):
- contextFilename snapshot honored
- parent-symlink escape rejected
- nested real subdir accepted
- restartMcpServer survives 1.2s response with 1s default timeout
- restartMcpServer honors a 50ms caller override

Typecheck clean across cli / sdk-typescript / core.
1604/1604 unit tests pass.

* fix(serve): fold-in 1 — address 16:32:44-round review on #4282

Follow-up addressing the 8 unresolved review threads opened on PR
shipping in this same #4297; addresses correctness gaps + missing
test coverage that would otherwise let regressions ride into main.

Behavior fix:
- broadcastWorkspaceEvent gains a `skipSessionId` parameter; when
  `setSessionApprovalMode` runs with `persist:true`, the broadcast
  skips the requesting session so it doesn't receive the same
  `approval_mode_changed` event twice (once via session-scoped
  publish + once via broadcast). The SDK reducer's
  `approvalModeChangedCount` now increments by 1, not 2, on the
  requesting client (peers still see 1 via the broadcast).
  Addresses #3260501134.

Observability + posture:
- broadcastWorkspaceEvent now mirrors PR 16's publishWorkspaceEvent
  member: per-entry success/failure accounting + an "ALL buses
  dropped" stderr elevation. The previous local helper silently
  swallowed every publish failure. Addresses #3260501126.
- WorkspaceInitPathEscapeError + WorkspaceInitSymlinkError typed
  classes for the two boundary guards in initWorkspace, mapped to
  HTTP 400 by sendBridgeError. Previous generic `Error` fell
  through to the 500 handler, telling operators "daemon broken"
  when the actual fix was workspace-config correction. Addresses
  #3260501161.

Public surface symmetry:
- Re-export McpServerNotFoundError, McpServerRestartFailedError,
  WorkspaceInitPathEscapeError, WorkspaceInitSymlinkError from the
  serve barrel. External embeds matching these via `instanceof`
  no longer need deep imports. Addresses #3260501163.

Test coverage:
- restartMcpServer bridge tests (5): success + event broadcast,
  soft-skip + refused event, McpServerNotFoundError translation,
  McpServerRestartFailedError translation, originator clientId
  stamping. Addresses #3260501141.
- sendBridgeError mapping tests (4): McpServerNotFoundError → 404,
  McpServerRestartFailedError → 502, WorkspaceInitPathEscapeError
  → 400, WorkspaceInitSymlinkError → 400. Addresses #3260501148.
- initWorkspace boundary guard tests (2 added): symlink-at-target
  rejected, contextFilename '../outside.md' rejected. Addresses
  #3260501157.
- TrustGateError tests assert the typed class via `.toThrow(TrustGateError)`,
  not just message text. Addresses #3260501165.

Also updates the existing fold-in 4 S2 broadcast test to reflect
the new no-duplicate semantics on the requesting session.

Typecheck clean across cli / sdk-typescript / core.
1615/1615 unit tests pass.

* fix(serve): fold-in 2 — copilot + wenshao review on #4297

Round-2 reviewer adoption on the same PR:

Critical fixes:
- `restartMcpServer` JSDoc documents `timeoutMs: 0` as "disable the
  timeout entirely", but the `> 0` guard in `fetchWithTimeout`
  rejected `0` and silently fell back to the 30s client default.
  Loosened the guard to `>= 0` so `0` flows through to the
  no-timeout branch via the existing truthiness check; NaN /
  negative inputs still coerce to the client default. Addresses
  duplicate reports from copilot (#3260577538) and wenshao
  (#3260661833).
- TS2322 in the slow-fetch test stub: `resolveResponse` was typed
  against `import('undici-types').Response` but assigned a
  `(v: Response) => void`. Re-typed against the global `Response`
  throughout. Caught only by tsc runs that include the test
  files. Addresses #3260663072.

Test fidelity:
- Slow-fetch stub now observes `init.signal` and rejects on abort,
  so a regression that drops the per-call `timeoutMs` override
  will reliably fail the test instead of resolving after the
  timer fired (false-negative coverage). Addresses #3260577600.
- New test pinning the `timeoutMs: 0` semantics: 1ms client
  default + a stub that resolves after 50ms. Without the `>= 0`
  fix, the call would abort at 1ms; with it, the explicit
  `0` disables the timer and the call completes.

Bug fixes:
- `runQwenServe.contextFilenameForInit` previously called
  `String(arr[0])` on the array branch, producing a literal
  `"[object Object]"` filename for hand-edited bad data. Now
  validates each element with `typeof === 'string'` and falls
  back to `undefined` (so the bridge uses its
  `getCurrentGeminiMdFilename()` default) when no string is
  found. Addresses #3260577641.

Documentation drift:
- `Config.getDisabledTools()` JSDoc rewritten to describe the
  mutable-via-`setDisabledTools()` semantics introduced by P2-2,
  and the "registration-time only / no retroactive unregister"
  contract that pairs with it. Old comment claimed the set was
  frozen at construction. Addresses #3260577677.

Observability:
- `acpAgent` MCP-restart `loadSettings` failure now surfaces a
  stderr line naming the server + the underlying error, instead
  of silently swallowing it. The documented "toggle + restart"
  workflow used to break with zero diagnostic when settings.json
  was corrupted or unreadable. Addresses #3260663303.

Code organization:
- Moved `canonicalizeExistingAncestor` after `describeStatKind` so
  the latter's JSDoc is no longer orphaned (TypeScript only
  associates the last `/** ... */` block before a declaration).
  Addresses #3260668618.

Typecheck clean across cli / sdk-typescript / core.
1616/1616 unit tests pass.

* fix(serve): fold-in 3 — read merged scope on MCP restart refresh

Critical bug from wenshao review (#3260725526) on PR #4297:
the P2-2 acpAgent re-read narrowed `Config.disabledTools` to
`SettingScope.Workspace` alone, dropping User / System scope
entries. The bootstrap Config received `merged.tools?.disabled`
(union of all scopes), so user-level / system-level disables
worked at boot — but the first `mcp restart` would replace the
in-memory set with the workspace scope alone, silently re-enabling
any tool that was disabled at a higher scope but absent from the
workspace file.

The asymmetry vs. the persist-write path is deliberate and
documented:
- Reads (here): merged — match the bootstrap Config snapshot,
  preserve user/system policy.
- Writes (`runQwenServe.persistDisabledTools`): workspace scope —
  don't bake higher-scope entries into the workspace file
  (per-#4282 fold-in 1 H2 fix).

Two paths look alike but answer different questions.

Typecheck clean across cli / sdk-typescript / core.
1616/1616 unit tests pass.

* fix(test): fold-in 4 — wire timeoutMs:0 stub to init.signal

Critical follow-up from wenshao (#3260810242) on PR #4297:
the new `timeoutMs: 0` regression test (added in fold-in 2)
inherited the same flaw it was meant to prevent — the slow-fetch
stub didn't observe `init.signal`, so a regression that ignored
the `0` override would fire the AbortController at the 1ms client
default but the stub would keep the promise pending. The 50ms
`resolveResponse` would win, the test would still pass, and the
documented "0 disables timeout" contract would be unprotected.

Mirrored the listener pattern already used by the two sibling
tests in fold-in 2 — `init.signal.addEventListener('abort', () =>
reject(...))`. Now a regression that re-rejects `0` triggers the
abort, the stub rejects, the test fails.

8/8 restartMcpServer SDK tests pass; SDK typecheck clean.

* fix(serve): fold-in 5 — TOCTOU + setDisabledTools coverage

Two new critical reviews from wenshao on PR #4297:

C1 — TOCTOU between lstat and writeFile (#3260836305):
The `lstat(target)` symlink check and the subsequent `writeFile`
were two separate syscalls, leaving a race window where a local
attacker with workspace write access could substitute a symlink
between them. With `force: true`, `writeFile` would follow the
link and truncate an external target.

The `action === 'created'` path now uses `fs.open(target, 'wx')`
(O_WRONLY|O_CREAT|O_EXCL), which atomically refuses any
pre-existing inode (regular file, dir, OR symlink) at the target
path. EEXIST after the absence check most plausibly means a
race-created symlink, so we throw `WorkspaceInitSymlinkError(kind:
'target')` — same typed class the route maps to 400.

The `force: true` overwrite path retains the existing TOCTOU as a
documented limitation; closing it requires `O_NOFOLLOW`-aware open
which the post-PR18 `WorkspaceFileSystem` migration will provide.

C2 — P2-2 zero test coverage (#3260836302):
The `setDisabledTools` runtime sync was the only Wave-4 P2 fix
without a dedicated test. Added 5 Config-level tests:
- Initializes from `disabledTools` ConfigParameters
- Defaults to empty set when omitted
- `setDisabledTools` replaces the live snapshot
- Defensive copy: caller-set mutations don't leak into the live snapshot
- Accepts an empty set (clears live snapshot)

Plus a TOCTOU regression test in httpAcpBridge.test.ts that
spies fs.lstat / fs.readFile to simulate the race window:
pre-creates a symlink, makes lstat lie about it, asserts the
'wx' open catches the racing inode and throws the typed
`WorkspaceInitSymlinkError(kind: 'target')`.

1622/1622 unit tests pass; typecheck clean across cli /
sdk-typescript / core.

* fix(serve): fold-in 6 — count actual skips in broadcast alarm

DeepSeek review on #4297 (#3261079572):
`broadcastWorkspaceEvent` unconditionally subtracted 1 from the
`eligible` recipient count whenever `skipSessionId` was set, even
when the id matched zero live sessions (caller mistake, stale id,
or the matching session was just torn down between resolution and
broadcast). In a single-session workspace that's the difference
between `eligible = 0` (alarm suppressed) and `eligible = 1`
(alarm fires when the publish failed) — silently losing the
all-dropped breadcrumb the telemetry was meant to surface.

Today's call sites pass real session ids so the bug doesn't
manifest in practice, but the defensive shape is small: track
`skippedCount` inside the loop and subtract that, so the alarm
condition is self-consistent regardless of how the caller mis-uses
the param.

162/162 bridge tests pass; CLI typecheck clean.

* fix(serve): fold-in 7 — close overwrite TOCTOU, harden boot + diagnostics

Round-7 review on PR #4297. Three critical fixes + one suggestion
test, plus a regression test for the overwrite TOCTOU close.

C1 — force:true overwrite TOCTOU (#3262615446):
The fold-in 5 fix only closed the `'created'` action via 'wx';
the `'overwrote'` branch still used plain `fs.writeFile`, so a
local writer could swap the verified regular file to a symlink
between the lstat/readFile checks and the write and have the
forced overwrite truncate an external target. Switched to
`fs.open(target, O_WRONLY | O_TRUNC | O_NOFOLLOW)` — `O_NOFOLLOW`
makes open() fail with ELOOP on a symlink at the final component
even under race. ELOOP / ENOENT (race-deleted) translate to
`WorkspaceInitSymlinkError(kind: 'target')` so the route still
maps to a structured 400 instead of a generic 500.

C2 — settings.json corrupt blocks daemon boot (#3262625091):
`loadSettings(boundWorkspace)` at boot had no try/catch — a
corrupted, malformed, or temporarily unreadable settings file
threw synchronously and prevented daemon startup. Pre-PR this
never happened because settings were read lazily inside request
handlers. Wrapped in try/catch with stderr fallback so the daemon
keeps booting (with the bridge's default context filename) when
the file is broken.

C3 — malformed `tools.disabled` clears policy silently (#3262625101):
When `merged.tools?.disabled` is present but not an array
(boolean / string / object from a hand-edited settings.json), the
ternary `Array.isArray(...) ? ... : []` substituted an empty list
without firing the surrounding catch block. After an MCP restart
every disabled tool would silently re-register. Added an explicit
`!Array.isArray && !== undefined` check that stderr-logs the
malformed type before clearing — operators see the
misconfiguration instead of a stealth re-enable.

S1 — contextFilename extraction tested (#3262690842):
Lifted the inline `firstStringInArray` + branching into an
exported `extractContextFilename(value: unknown)` helper and
added `runQwenServe.test.ts` with 5 tests covering the four
branches the suggestion called out: non-empty string, array with
strings, array with no strings, non-string non-array.

Plus a TOCTOU regression test for the overwrite path that
verifies `O_NOFOLLOW` returns `WorkspaceInitSymlinkError(kind:
'target')` when the file is race-substituted with a symlink
behind the lstat/readFile mocks.

S2 (acpAgent restart-handler integration test #3262690845) is
deferred — Config-level coverage of `setDisabledTools` already
locks the load-bearing surface (5 tests in fold-in 5), and
adding a full acpAgent integration test requires heavy ext-method
plumbing. The new C3 stderr diagnostic plus existing tests give
us the regression signal we need without that scaffolding.

1627/1627 unit tests pass; typecheck clean across cli /
sdk-typescript / core / acp-bridge.

* fix(serve): fold-in 8 — split ELOOP / ENOENT diagnostic in overwrite path

qwen-latest review on PR #4297 (#3262861754):
The fold-in 7 ELOOP/ENOENT branch shared one error message that
said "swapped to a symlink." That's accurate for ELOOP (genuine
O_NOFOLLOW rejection — likely an attack race) but misleading for
ENOENT in the overwrite path: there `readFile` just succeeded
proving the file existed, so ENOENT means the file was DELETED
between the content check and the open — a benign race with a
concurrent writer (git checkout, editor save, lockfile rename),
NOT a symlink swap. An operator seeing the symlink language for
a benign delete would `ls -la`, see no symlink, and waste time
hunting an attack that didn't happen.

Split into two messages:
- ELOOP: "swapped to a symlink between the content check and the
  overwrite — refusing to follow it"
- ENOENT: "deleted between the content check and the overwrite
  (likely a concurrent writer) — refusing to recreate blindly"

Both still surface as `WorkspaceInitSymlinkError(kind: 'target')`
so the route maps to a structured 400; the class doubles as the
workspace-init race-condition bucket with kind='target' meaning
"target inode misbehaved at write time" generally.

Updated the existing fold-in 7 TOCTOU test to assert the ELOOP
message specifically, and added a new ENOENT race-delete test
that mocks lstat/readFile to land on the overwrote action against
a non-existent path — verifies the message says "deleted" and
NOT "swapped to a symlink."

170/170 bridge tests pass; CLI typecheck clean.

* fix(serve): fold-in 9 — route MCP restart through registry cleanup wrapper

gpt-5.5 critical review on PR #4297 (#3263088414):

The fold-in 5 P2-2 fix refreshed `Config.disabledTools` from merged
settings, but then called `manager.discoverMcpToolsForServer()`
directly — bypassing the `ToolRegistry.discoverToolsForServer`
wrapper that PURGES the server's existing `DiscoveredMCPTool`
entries (and `revealedDeferred` markers) plus its prompts before
rediscovery. Without the cleanup, `registerTool` only consulted
the refreshed `disabledTools` set for NEWLY-discovered tools —
entries already in the registry from the prior MCP boot kept
serving requests. Net effect: toggle-disable-then-restart
silently left the disabled tool live, breaking the documented
"toggle + restart" workflow that P2-2 was meant to fix.

Routed through `toolRegistry.discoverToolsForServer(serverName)`
which:
1. Removes existing `DiscoveredMCPTool` entries for this server
2. Drops their `revealedDeferred` reveal state
3. Removes the server's prompts via `removePromptsByServer`
4. THEN delegates to `manager.discoverMcpToolsForServer` for the
   actual reconnect + rediscover

The pre-discovery budget / in-flight checks still go through the
`manager` reference (which is the same object the registry
wrapper would forward to) — so soft-skip semantics for
`budget_would_exceed`, `in_flight`, `disabled` are preserved.

CLI typecheck clean; 403/403 server + bridge tests pass.

* fix(serve): fold-in 10 — qwen-latest 05:45-round review on #4297

5 review threads from qwen-latest's late round on PR #4297 (now closed
in favor of #4313 against `daemon_mode_b_main`). 1 critical + 4
suggestions, all adopted.

C1 — extractContextFilename / getCurrentGeminiMdFilename divergence
(#3263954685): with `context.fileName: ['  ', 'AGENTS.md']`, the
daemon parent's `extractContextFilename` (which skips empty entries)
wrote `AGENTS.md`, but the ACP child's `getCurrentGeminiMdFilename`
(which returned `arr[0]` unconditionally) read `''`. The init'd file
was orphaned. Aligned `getCurrentGeminiMdFilename` to skip empty
entries with the same semantics, falling back to
`DEFAULT_CONTEXT_FILENAME` when all entries are empty.

S2 — WorkspaceInitSymlinkError reused for non-symlink races
(#3263954690): the EEXIST race-create and ENOENT race-delete cases
were surfacing as `code: 'workspace_init_symlink'`, misleading
operators into hunting symlink attacks for benign concurrent-
modification windows. Split into a sibling `WorkspaceInitRaceError`
class (`kind: 'eexist' | 'enoent'`, HTTP code
`workspace_init_race`). The genuine symlink class stays for ELOOP,
lstat-detected target symlinks, and parent-realpath escapes.

S3 — fsConstants.O_NOFOLLOW defensive `?? 0` (#3263954697): matches
the existing codebase convention in
`core/src/utils/{sessionStorageUtils,gitDiff}.ts` and
`cli/src/ui/utils/customBanner.ts`. Functionally a no-op (JS
bitwise coerces undefined to 0) but consistent.

S5 — Parent-directory TOCTOU still open (#3263954707): O_NOFOLLOW
only protects the final path component; a local writer could swap
a real parent dir for a symlink between
`canonicalizeExistingAncestor` and `fs.open`. Added
`verifyParentWithinWorkspace` post-open helper that re-realpaths
`path.dirname(target)` and refuses with
`WorkspaceInitSymlinkError(kind: 'parent')` if the parent moved.
On the create path (where we just opened with `'wx'`), the failure
also unlinks the file we just made best-effort. Residual race
window narrowed from "between pre-check and open" to "between
post-open realpath and writeFile" — sub-millisecond, documented as
accepted Stage-1 trust posture.

S4 — broadcastWorkspaceEvent vs publishWorkspaceEvent stale comment
(#3263954688): the "now removed" comment was inaccurate (5 call
sites still use the closure). Replaced with an accurate
description of why both coexist (factory closure can't `this`-call
proxy member; closure also takes `skipSessionId` for persisted
approval-mode mirror) and a TODO marker for future helper extraction.

Two existing tests updated to assert the new `WorkspaceInitRaceError`
class for EEXIST / ENOENT scenarios (the symlink-class assertions
are preserved for ELOOP / lstat / parent cases).

1759/1759 unit tests pass; typecheck clean across all 4 packages.

* feat(acp-bridge): F1 — acp-bridge package self-sufficiency (#4175 mechanical lift + BridgeFileSystem seam) (#4319)

* refactor(acp-bridge): lift defaultSpawnChannelFactory to acp-bridge/spawnChannel (#4175 F1 step 1)

First mechanical lift of #4175 F1 (acp-bridge package self-sufficiency).
Moves the production spawn factory + its `killChild` helper +
`SCRUBBED_CHILD_ENV_KEYS` denylist + `KILL_HARD_DEADLINE_MS` constant
from `cli/src/serve/httpAcpBridge.ts` (~283 lines) to
`@qwen-code/acp-bridge/spawnChannel`. This unblocks
`channels/base/AcpBridge.ts` and `vscode-ide-companion`'s
acpConnection from each reimplementing the child lifecycle — they can
now consume the same primitive.

Backward compatible: `cli/src/serve/httpAcpBridge.ts` imports the
lifted factory and re-exports it, so existing references in
`cli/src/serve/index.ts:90` and the factory's own internal usage
(`opts.channelFactory ?? defaultSpawnChannelFactory`) keep resolving.
Bridge tests that mock `defaultSpawnChannelFactory` via
`BridgeOptions.channelFactory` are unaffected.

Side cleanups: drops `spawn` / `ChildProcess` / `Readable` / `Writable`
/ `ndJsonStream` / `MissingCliEntryError` imports from
httpAcpBridge.ts (all only used by the lifted spawn factory).

- 44/44 acp-bridge tests pass
- 174/174 cli httpAcpBridge tests pass
- typecheck clean across acp-bridge + cli

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* refactor(acp-bridge): lift BridgeClient + permission types to acp-bridge/bridgeClient (#4175 F1 step 2)

Second mechanical lift of #4175 F1 (acp-bridge package self-sufficiency).
Moves `BridgeClient` class (~700 LOC) + `PendingPermission` interface +
`PermissionResolutionRecord` interface + `MAX_RESOLVED_PERMISSION_RECORDS`
constant + early-event capacity constants + `describeStatKind` and
`sliceLineRange` helpers from `cli/src/serve/httpAcpBridge.ts` to
`@qwen-code/acp-bridge/bridgeClient`.

Design choice for SessionEntry boundary: introduce a minimal
`BridgeClientSessionEntry` interface in bridgeClient.ts with only the
four fields BridgeClient actually reads from the factory's richer
`SessionEntry` (`sessionId`, `events`, `pendingPermissionIds`,
`activePromptOriginatorClientId`). The factory's `SessionEntry`
structurally satisfies it — TypeScript's structural typing enforces
the match at the `resolveEntry` callback signature, so no explicit
conversion is required and the bridge package stays free of daemon-host
session-bookkeeping types.

Cross-package writeStderrLine handling: inline the 3-line helper in
bridgeClient.ts (mirrors the spawnChannel.ts pattern from F1 step 1)
so acp-bridge has no reverse dependency on `cli/src/utils/stdioHelpers`.

httpAcpBridge.ts shrinks from 4406 LOC to 3647 LOC (-759 lines).
Removed ACP SDK imports that only BridgeClient consumed: `Client`,
`RequestPermissionRequest`, `WriteTextFileRequest`,
`WriteTextFileResponse`, `ReadTextFileRequest`, `ReadTextFileResponse`,
`SessionNotification`. Kept the ones the factory still uses
(`CancelNotification`, `PromptRequest`, `RequestPermissionResponse`,
`SetSessionModelRequest`, `SetSessionModelResponse`).

Backward compatible: httpAcpBridge.ts re-exports `BridgeClient`,
`BridgeClientSessionEntry`, `PendingPermission`,
`PermissionResolutionRecord`, and `MAX_RESOLVED_PERMISSION_RECORDS` so
the `ChannelInfo.client: BridgeClient` field declaration below + any
embedder reaching into these types keep resolving.

- 44/44 acp-bridge tests pass
- 174/174 cli httpAcpBridge tests pass
- 229/229 cli server tests pass
- typecheck clean across acp-bridge + cli

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* refactor(acp-bridge): lift createHttpAcpBridge factory to acp-bridge/bridge (#4175 F1 step 3)

Third + final mechanical lift of #4175 F1 (acp-bridge package
self-sufficiency). Moves the `createHttpAcpBridge` factory closure
(~3000 LOC) + `ChannelInfo` + `SessionEntry` interfaces + factory-only
helpers (`canonicalizeExistingAncestor`, `verifyParentWithinWorkspace`,
`withTimeout`, `isServeDebugLoggingEnabled`, `writeServeDebugLine`,
`hasControlCharacter`) + factory constants (`DEFAULT_INIT_TIMEOUT_MS`,
`MCP_RESTART_TIMEOUT_MS`, `DEFAULT_MAX_SESSIONS`, `MAX_EVENT_RING_SIZE`,
`DEFAULT_PERMISSION_TIMEOUT_MS`, `DEFAULT_MAX_PENDING_PER_SESSION`,
`MAX_DISPLAY_NAME_LENGTH`) from `cli/src/serve/httpAcpBridge.ts` to
`@qwen-code/acp-bridge/bridge`.

`cli/src/serve/httpAcpBridge.ts` shrinks from 3647 LOC to 97 LOC — a
pure re-export shim that preserves every existing relative import
path (`./httpAcpBridge.js`) so `server.ts`, `runQwenServe.ts`,
`workspaceAgents.ts`, `workspaceMemory.ts`, `index.ts`, plus the bridge
test suite, keep resolving without any call-site changes.

The new `bridge.ts` reuses what was already in acp-bridge (errors,
types, options, status helpers, channel types, event bus, workspace
paths) via local relative imports — no reverse dependency on `cli`.
`writeStderrLine` is inlined at the top of `bridge.ts` (same pattern as
`spawnChannel.ts` + `bridgeClient.ts` from F1 steps 1-2) so the
package self-contained promise holds.

Cumulative F1 impact across the 3 mechanical lift steps:
- httpAcpBridge.ts: 4682 LOC → 97 LOC (-4585 lines; the original file
  was 98% bridge core, 2% backward-compat re-exports)
- 3 new files in acp-bridge: spawnChannel.ts (~270 LOC), bridgeClient.ts
  (~745 LOC), bridge.ts (~3515 LOC)
- All daemon-host concerns (env snapshot, daemon preflight cells)
  remain in `cli/src/serve/daemonStatusProvider.ts` and reach the
  bridge through the `BridgeOptions.statusProvider` seam frozen by
  PR 22b/2.

- 735/735 cli serve tests pass across 17 files
- 174/174 cli httpAcpBridge tests pass
- 44/44 acp-bridge tests pass
- typecheck clean across acp-bridge + cli

`packages/cli/src/serve/httpAcpBridge.test.ts` (~6600 LOC) is
intentionally NOT moved in this commit — it currently imports
`createHttpAcpBridge` / `defaultSpawnChannelFactory` / `BridgeClient`
via the cli shim and keeps passing without changes. Moving it to
`acp-bridge/src/bridge.test.ts` is a follow-up worth tracking
separately so the production-code lift can land + be reviewed cleanly.

The `BridgeFileSystem` injection seam (originally bundled into F1 as
the 22b' scope) is also deferred to a follow-up so the mechanical lift
stays mechanical — design + implementation of the fs injection is its
own discussion.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* feat(acp-bridge): add BridgeFileSystem injection seam (#4175 F1 step 5, 22b' scope)

Adds the `BridgeFileSystem` injection seam originally scoped as #4175
22b'. When a `BridgeFileSystem` is wired through
`BridgeOptions.fileSystem`, `BridgeClient.readTextFile` and
`BridgeClient.writeTextFile` delegate to it instead of running their
inline `fs.realpath` / `fs.writeFile` / `fs.readFile` proxy.

This unblocks production `qwen serve` plumbing PR 18's
`WorkspaceFileSystem` (TOCTOU guards, symlink-substitution checks,
trust gate, `.gitignore`, audit hooks) into the ACP fs methods —
closing the `ws.ts:613` follow-up thread that has been tracked since
PR 18 landed. The serve-side adapter that wraps `WorkspaceFileSystem`
+ the `runQwenServe` wiring are intentionally split into the
immediate-follow-up so this PR stays focused on the seam design.

Backward compatible: `fileSystem` is optional on `BridgeOptions`.
Tests, Mode A in-process consumers, channels (`packages/channels/base/
AcpBridge.ts`), and the VSCode IDE companion all keep working
unchanged — they omit the field and `BridgeClient` falls through to
the inline proxy that has been the Stage 1 default since #3889.

API:
- `BridgeFileSystem.readText(params: ReadTextFileRequest):
  Promise<ReadTextFileResponse>`
- `BridgeFileSystem.writeText(params: WriteTextFileRequest):
  Promise<WriteTextFileResponse>`

The interface mirrors ACP SDK request/response types directly so the
adapter does the minimum amount of translation (`{ path, content }`
↔ `WorkspaceFileSystem`'s `ResolvedPath` brand types + options bag).

- 735/735 cli serve tests pass (inline fallback path preserved)
- 44/44 acp-bridge tests pass
- typecheck + eslint clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): catch README + stale source comments up to F1 lift

Self-review fold-in: post-F1 the package README still said "PR 22a"
and listed `BridgeClient` / `createHttpAcpBridge` /
`defaultSpawnChannelFactory` under "What's not here yet" — both
contradicted by this PR. Updated:

- README lift-history table now shows PR 22a / 22b/1 / 22b/2 as
  merged and F1 (this PR) as the slice that closes the bridge core
  + adds `BridgeFileSystem`. F3 PR 24 row aligned to the
  feature-cohesive plan.
- "What's here today" now documents `spawnChannel`, `bridgeClient`,
  `bridge`, `bridgeFileSystem` modules.
- "What's not here yet" section removed (its 2 bullets are both
  resolved by F1).
- Subpath import list updated to enumerate all 14 subpaths.
- Backward-compat section updated to call out the 97-line shim and
  the 6 consuming files that still import via `./httpAcpBridge.js`.

Source-comment line-number drift:
- `channel.ts:12` no longer claims `defaultSpawnChannelFactory` is
  "still in cli/src/serve/httpAcpBridge.ts" — points to the lifted
  location.
- `permission.ts:33` + `permission.ts:45` no longer reference
  `httpAcpBridge.ts:1096-1106` / `httpAcpBridge.ts:1003` (file is
  now 97 lines after F1). Updated to point at the structurally-
  equivalent locations inside the lifted `bridgeClient.ts`.
- `permission.ts:7` no longer says first-responder still lives in
  `cli/src/serve/httpAcpBridge.ts` — points at the bridgeClient.ts
  location.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): adopt 3 Copilot review comments on F1 doc accuracy

Folds in 3 of 4 Copilot inline comments from #4319 review:

1. `bridgeClient.ts` writeTextFile preserveMode comment said "fall
   through to umask defaults" for new files, but the code passes
   `mode: preserveMode?.mode ?? 0o600` to `fs.writeFile`. Updated the
   "BkwQW" comment + the inner catch-block comment to clarify that
   new files actually get the `0o600` default applied at writeFile
   time (NOT umask defaults — the explicit `mode` arg bypasses umask
   for atomicity per the `Blehd` comment block).

2. `bridgeFileSystem.ts` JSDoc referenced
   `cli/src/serve/bridgeFileSystemAdapter.ts` as if the file exists,
   but it's deferred to the immediate F1 follow-up PR. Reworded as
   "the immediate follow-up PR will land a serve-side adapter" so
   reviewers don't grep for a non-existent file.

3. `bridgeOptions.ts` `fileSystem` field JSDoc had the same wording
   issue ("Production `qwen serve` wires this to..."). Same fix — now
   says "The immediate F1 follow-up will land a serve-side adapter"
   so the deferred state is obvious.

Declined from this review round:

- Copilot inline #1 (`spawnChannel.ts:155` stderr forwarder drops
  empty lines): pre-existing behavior since #3889. F1 lifted verbatim
  — not a regression introduced here. Out of scope for a lift PR.
- github-actions bot summary: most items are pre-existing notes
  (TOCTOU residual race, SCRUBBED_CHILD_ENV_KEYS allowlist concern,
  sliceLineRange benchmark threshold) on code the F1 lift moved
  verbatim. One ("httpAcpBridge.ts still has ~3700 LOC") is a false
  positive — the file is 97 LOC after F1. Others are cosmetic
  refactors (extract FIXME to tracking issue, ARCHITECTURE_DECISIONS
  doc system, deprecation timeline) that aren't worth churning the
  lift PR over.

- 44/44 acp-bridge tests pass
- typecheck clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): tighten BridgeFileSystem contract + re-export type from shim

Self-review + code-reviewer agent fold-in, two changes:

1. `cli/src/serve/httpAcpBridge.ts` shim now re-exports
   `BridgeFileSystem` from `@qwen-code/acp-bridge/bridgeFileSystem`
   so the immediate F1 follow-up adapter (in `cli/src/serve/`)
   can import it via the established `./httpAcpBridge.js` path
   like every other daemon-side bridge import does. Without this
   the adapter would need to deep-import from acp-bridge while
   every other serve file goes through the shim — inconsistent.

2. `BridgeFileSystem.readText` + `writeText` JSDoc now spells out
   the two defensive gates the inline proxy carried (non-regular-
   file rejection + 100 MiB buffered-size cap for reads;
   write-then-rename atomicity + dangling-symlink walk-through +
   mode preservation + `0o600` new-file default for writes). When
   a `BridgeFileSystem` is injected, the inline path is FULLY
   bypassed — without the contract spelled out, a future adapter
   author could silently drop the `/dev/zero` / 500 MB log RSS
   defenses the inline path established.

Note on F1 CI: this PR targets `daemon_mode_b_main` but the
`.github/workflows/ci.yml` `pull_request` trigger is scoped to
`branches: main / release/**`, so the main CI workflow (Lint /
Test on Linux/macOS/Windows / CodeQL) does NOT run on this PR.
This is a by-design side effect of the new feature-cohesive
branching strategy — `daemon_mode_b_main → main` periodic merges
will trigger the full CI matrix, providing safety net coverage
before any F-series work lands on `main`. Locally verified:
- 174/174 cli httpAcpBridge tests pass
- 44/44 acp-bridge tests pass
- 735/735 cli serve tests pass
- typecheck clean across acp-bridge + cli

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* test(acp-bridge): cover BridgeFileSystem injection seam + extract shared writeStderrLine (#4319 wenshao review)

Folds in wenshao review on #4319:

1. **[Critical]** zero test coverage for the F1 step 5 `BridgeFileSystem`
   delegation branches in `BridgeClient.writeTextFile` /
   `BridgeClient.readTextFile` and the factory's
   `opts.fileSystem` → constructor positional-arg forwarding.

   New `packages/acp-bridge/src/bridgeClient.test.ts` adds 6 tests
   covering:
   - writeTextFile delegates to injected fileSystem.writeText (inline
     proxy fully bypassed; `fakeFs.writeText` called with the original
     params; `readText` mock not invoked)
   - writeTextFile invalid-path call succeeds purely via the mock
     when fileSystem is injected (proof that the inline `fs.realpath`
     path doesn't run)
   - readTextFile delegates to injected fileSystem.readText
   - readTextFile propagates injection errors to the caller
   - inline-fallback regression guard: write actually hits disk via
     the inline proxy when fileSystem is omitted (real tmp file
     round-trip)
   - same for read

   Why these matter: the 7-arg `BridgeClient` constructor places
   `fileSystem` at the tail as optional. A reordering — or dropping
   the arg from `bridge.ts` factory's `new BridgeClient(..., opts.fileSystem)`
   call — would silently bypass the adapter in production and the
   inline `fs.writeFile` raw-path would run with no audit / trust /
   TOCTOU coverage. The delegation tests would catch that because
   the mock fileSystem would never be invoked.

2. **[Suggestion]** `writeStderrLine` was defined identically in
   `bridge.ts:117` and `bridgeClient.ts:30` (22 call sites across the
   two files). Both consumers live in the SAME `@qwen-code/acp-bridge`
   package, so the original "no reverse-dep on cli" justification
   doesn't apply within the package. Extracted to
   `packages/acp-bridge/src/internal/stderrLine.ts` — a single source
   of truth that future behavior changes (timestamp prefix, log
   level, structured field) can edit once. `internal/` subpath is
   intentionally not in `package.json`'s `exports`, keeping the
   helper package-private. `spawnChannel.ts` deliberately does NOT
   consume it (its stderr writes use `process.stderr.write(prefix +
   line + '\n')` directly because each line carries its own
   `[serve pid=… cwd=…]` line prefix).

- 6/6 new BridgeFileSystem-seam tests pass
- 50/50 acp-bridge total (44 existing + 6 new)
- 174/174 cli httpAcpBridge tests pass (no regression from refactor)
- typecheck + eslint clean

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* test(acp-bridge): cover defaultSpawnChannelFactory env scrubbing + fix bridge.ts comment refs (#4319 wenshao round 2)

Folds in wenshao review on #4319 round 2 — 1 Critical + 2 Suggestions:

1. **[Critical] spawnChannel.ts has 0 unit tests, security-critical
   paths untested.** Now that `defaultSpawnChannelFactory` is a public
   export of `@qwen-code/acp-bridge`, channels + IDE consumers can't
   rely on cli-package integration tests for env-scrubbing guarantees.

   Refactored the inline env-scrubbing logic into a pure exported
   helper `scrubChildEnv(source, scrubbed, overrides)`. Behavior is
   byte-identical to the pre-extraction inline implementation; the
   factory body now reads:

       const childEnv = scrubChildEnv(
         process.env, SCRUBBED_CHILD_ENV_KEYS, childEnvOverrides);

   Added `packages/acp-bridge/src/spawnChannel.test.ts` with 12 tests
   covering:
   - shallow-clone (no aliasing into live process.env)
   - QWEN_SERVER_TOKEN stripping
   - non-scrubbed vars pass through
   - override-add a new key
   - override-replace an existing key
   - override with undefined deletes the key (PR 14 fix #4247 wenshao R5)
   - override CANNOT re-introduce a scrubbed key (defense in depth)
   - override CANNOT undo the scrub by setting undefined for a scrubbed key
   - override-apply-after-scrub ordering invariant
   - empty overrides equals no overrides
   - multi-key scrub for forward-compat (the WARNING comment on
     SCRUBBED_CHILD_ENV_KEYS anticipates a future sandboxed-agent
     mode expanding the denylist; this verifies the loop already
     handles that)

   The killChild SIGTERM→SIGKILL escalation + STDERR_LINE_CAP_CHARS
   truncation are NOT covered yet — they require either real child
   processes or extensive node:child_process mocking; both are
   orthogonal to the env-scrubbing security guarantees wenshao
   explicitly called out, and can land as a follow-up if anyone
   wants the full surface tested.

2. **[Suggestion] bridge.ts comments referenced a "consolidated re-
   export block earlier in this file" that doesn't exist in acp-bridge
   (only in the cli shim).** Fixed both occurrences (~line 292, ~line
   310) to point at the actual local import + the package barrel
   re-export.

3. **[Suggestion] bridge.ts canonicalizeWorkspace re-export comment
   referenced `./fs/paths.ts`.** Updated to mention the full lift
   chain: extracted to `cli/src/serve/fs/paths.ts` in PR 18, then
   lifted here to `./workspacePaths.ts` in PR 22b/1.

- 12/12 new spawn env-scrub tests pass
- 62/62 acp-bridge total (50 existing + 12 new spawn)
- 174/174 cli httpAcpBridge tests still pass (the factory's inline
  env-scrubbing refactor preserves byte-identical behavior)
- typecheck + eslint clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): fix 14-arg→7-arg typo in test docstring + simplify canonicalizeWorkspace re-export doc (#4319 wenshao round 3)

Folds in 2 of 3 wenshao Suggestions from #4319 round 3:

1. `bridgeClient.test.ts:20` JSDoc said "the 14-arg constructor's
   positional slot" — typo I introduced when writing the test in
   `fbc92bccf`. The same docstring correctly says "the constructor
   takes 7 positional args" at line 25. Updated to "7-arg".

2. `bridge.ts:3461` `canonicalizeWorkspace` re-export JSDoc no longer
   references the historical `cli/src/serve/fs/paths.ts` location.
   Reads cleaner as a present-tense pointer to `./workspacePaths.ts`
   (where the implementation actually lives now post-PR 22b/1).
   Git history covers the lift chain; the docstring should describe
   current state.

DECLINED + tracked separately:

- **[Critical]** `closeSession` + `killSession` use module-scoped
  `channelInfo` instead of `channelInfoForEntry(entry)` — channel-
  overlap edge case can kill the wrong channel. Wenshao explicitly
  notes "pre-existing bug preserved by the lift" — F1's mechanical-
  lift scope shouldn't carry behavior fixes, and the fix needs a
  channel-overlap regression test to land safely. Tracked as #4325.

- 62/62 acp-bridge tests pass (no regression from doc tweaks)
- typecheck + eslint clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): polish from second-pass self-review (cross-platform test + package metadata + dead tombstones)

Five small adoptions from a second-pass code-reviewer agent review on
F1 (no new external comments — pre-emptive cleanup before reviewer
returns):

1. **`bridge.ts:290-313`** — deleted two standalone "InvalidPermission
   OptionError / WorkspaceInit* / McpServer* lifted to bridgeErrors"
   tombstone comments. Pre-22b they were load-bearing (explained why
   the class wasn't `class`-defined inline at that file location).
   Post-F1 the symbols are imported at the top of the file and the
   comments sit between unrelated code (`writeServeDebugLine` /
   `MAX_DISPLAY_NAME_LENGTH` / `DEFAULT_INIT_TIMEOUT_MS`) with no
   anchor. Dead doc — removed.

2. **`README.md`** — `spawnChannel` entry now lists `scrubChildEnv`
   alongside `defaultSpawnChannelFactory` + `killChild` +
   `SCRUBBED_CHILD_ENV_KEYS`. Channels / VSCode IDE consume the
   package barrel so the helper should be visible in the inventory.

3. **`package.json:description`** — refreshed from the PR 22a wording
   ("EventBus, AcpChannel, in-memory channel, PermissionMediator
   interface") to include F1 additions (`createHttpAcpBridge` /
   `BridgeClient` / `defaultSpawnChannelFactory` / `BridgeFileSystem`).
   Visible on `npm view`-style tooling + IDE hover so worth keeping
   current.

4. **`bridgeClient.test.ts:92-115`** — swapped `/proc/no-such-file`
   for `/this/dir/never/exists/file.txt` and reworded the comment.
   `/proc/` is Linux-only; on macOS / Windows the inline proxy's
   dangling-symlink fallback would write through to a path under
   root rather than failing. Test passed regardless (mock assertion,
   not real disk) but the comment overstated portability.

5. **`spawnChannel.test.ts:36`** — added a comment block explaining
   why the test deliberately hand-rolls the SCRUBBED set instead of
   importing the production `SCRUBBED_CHILD_ENV_KEYS`. The
   decoupling is intentional (pure-function parameterized test +
   forward-guard for future denylist expansion) but a naive reader
   would think it's an oversight.

- 62/62 acp-bridge tests pass
- 174/174 cli httpAcpBridge.test.ts pass
- typecheck + eslint + pre-commit hooks clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(acp-bridge): bridge.ts security fold-in from #4297 review (3 issues)

Folds 3 unresolved review comments from the post-merge thread on #4297
(wenshao via qwen-latest agent) into F1 (#4319). All 3 touch
`acp-bridge/src/bridge.ts` — the same file F1 already moves the lifted
factory into — so consolidating here saves opening a separate
follow-up PR and keeps the security narrative in one reviewable
commit. The 2 cross-package fixes (`core/src/memory/const.ts` test
gap + `cli/src/serve/runQwenServe.ts` malformed-context fallback)
will land as their own small PRs after F1 merges.

#### Fix 1 (wenshao Critical, #4297 thread): `fs.unlink(target)`
arbitrary-file-deletion primitive in `verifyParentWithinWorkspace`
'create'-cleanup

After `fs.open(target, 'wx')` creates the empty file at the real
parent, an attacker with local workspace write access can swap the
parent directory for a symlink (`docs/` → `/etc`). The cleanup's
`fs.unlink(target)` re-resolves the TEXTUAL path through the
attacker's freshly-planted parent symlink, deleting whatever file
exists at the external location.

Fix: drop the `fs.unlink(target)` line. The 0-byte file at the
pre-race location is harmless (0 bytes, inside the workspace we'd
already verified) — leaving it over deleting an arbitrary external
file is the right safety trade. Comment block explains the
reasoning so future maintainers don't re-introduce the unlink.

#### Fix 2 (wenshao Critical): `O_TRUNC` arbitrary-file-truncation
primitive in workspace-init 'overwrite' branch

`O_TRUNC` causes the kernel to truncate the file to zero bytes AT
`open(2)` SYSCALL TIME — strictly before `verifyParentWithinWorkspace`
runs. A parent-symlink TOCTOU race between
`canonicalizeExistingAncestor` and this `open()` zeros the file at
the attacker-redirected location (arbitrary-file-truncation
primitive against any file the daemon UID can open). The pre-fix
code's own comment on `verifyParentWithinWorkspace` acknowledged
this as "Acceptable residual posture for the Stage-1 trust model";
wenshao pushed back that arbitrary-file-zeroing exceeds the
Stage-1 trust budget.

Fix: drop `O_TRUNC` from the open flags. Truncation moves to AFTER
`verifyParentWithinWorkspace` succeeds, via `fh.truncate(0)` on the
fd we already hold. fd-based truncate does NOT re-resolve the path
— an attacker swapping the parent symlink after we open can't
redirect the truncation.

#### Fix 3 (wenshao Suggestion): `canonicalizeExistingAncestor`
missing `ELOOP` catch

Circular symlinks in the parent path (`a -> b`, `b -> a`) cause
`fs.realpath` to fail with `ELOOP`. Without catching it, the error
propagates as an unstructured HTTP 500 instead of the typed
`WorkspaceInitSymlinkError` (HTTP 400) the route handler expects
from the workspace-init race-detection family.

Fix: add `'ELOOP'` to the caught error codes alongside `'ENOENT'`
and `'ENOTDIR'`. Walking up the parent chain when ELOOP hits at a
sub-component preserves the existing "walk to the deepest extant
ancestor" contract — the deepest realpath-able ancestor still
dictates the canonical prefix.

#### Why no new tests in this commit

- Fix 1 is a single-line removal: any regression that re-adds the
  unlink would be caught by reviewing the diff; existing 174-test
  `httpAcpBridge.test.ts` integration suite confirms the create-path
  still works (file is created + closed correctly; only the
  attacker-cleanup branch changes).
- Fix 2 is a structural move (truncate from open-time to post-verify);
  the existing overwrite-init integration tests confirm the
  end-to-end behavior is unchanged (file ends up empty after init).
  Adding a TOCTOU race regression test requires controlled
  filesystem-race simulation that exceeds reasonable test infra
  scope for this PR.
- Fix 3 is a one-word addition to an error code list; the
  `canonicalizeExistingAncestor` helper is module-private and the
  integration test for circular-symlink → typed 400 would require
  exporting it OR setting up a real circular-symlink workspace.
  Both routes widen scope beyond the security fix itself; the
  high-level behavior is verifiable by the existing route-error-
  mapping test pattern + diff review.

A follow-up PR can add the integration tests once the security fix
itself has shipped; the immediate priority is closing the
arbitrary-file-deletion + arbitrary-file-truncation primitives.

- 62/62 acp-bridge tests pass
- 174/174 cli httpAcpBridge.test.ts pass
- typecheck + eslint clean

#### Refs

- Original review on #4297 (wenshao via qwen-latest agent), post-
  merge, currently unresolvable on #4297 itself because that PR is
  already MERGED.
- Other 2 #4297 review threads (`const.ts` test coverage,
  `runQwenServe.ts` malformed-context observability) target files
  outside F1's scope and will land as separate follow-up PRs.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix: post-merge Codex P2 fold-in — MCP restart disabled-tools normalization + SDK timeout headroom (#4319)

Folds in 2 P2 findings from a Codex review run on `git diff main...HEAD`
of F1 PR #4319. Both are pre-existing in code merged into
`daemon_mode_b_main` before F1 was created (#4282 PR 17), but they're
tiny tactical fixes (~25 LOC + 1 LOC) on the same integration branch
the same reviewer (wenshao) already engages with, so folding into F1
saves an extra follow-up PR cycle.

#### Fix 1: normalize disabled tool names during MCP restart refresh

`packages/cli/src/acp-integration/acpAgent.ts:1563-1566`

The bootstrap path in `cli/src/config/config.ts:1426-1434` applies a
4-step normalization to `tools.disabled`:
  1. typeof string filter
  2. .trim()
  3. drop empty after trim
  4. dedupe via Set

The MCP-restart refresh path only did step 1, then stored the raw
strings. `ToolRegistry` checks disabled tools with EXACT
`Set.has(tool.name)`, so a tool disabled at boot as `' Foo '` (or
`'Foo\n'`) is no longer matched after `restartMcpServer` and gets
silently re-registered. This contradicts the documented "toggle +
restart" workflow that #4282 PR 17 advertised.

Fix: mirror the bootstrap normalization verbatim before
`setDisabledTools`. Adds 6 lines + a 7-line comment pointing at the
bootstrap reference for future maintainers.

#### Fix 2: add headroom to MCP restart SDK timeout

`packages/sdk-typescript/src/daemon/DaemonClient.ts:102`

The SDK's `MCP_RESTART_DEFAULT_TIMEOUT_MS` was EXACTLY 300_000ms, the
same ceiling the daemon's own `MCP_RESTART_TIMEOUT_MS` uses for the
upper bound on a single MCP rediscovery. For restarts that finish
(or fail with a typed `McpServerRestartFailedError` JSON envelope)
near 300s, the client `AbortSignal` could fire BEFORE the daemon had
finished serializing + transmitting the response, yielding a client
`TimeoutError` even though the daemon was still within its own
budget.

Fix: bump to 330_000ms (10% / 30s headroom over the daemon ceiling).
Comment updated to call out the race + the rationale for the
specific headroom value. Callers needing tighter caps still pass
their own `timeoutMs` to `restartMcpServer`.

#### Why folded into F1 vs separate follow-up PRs

These are post-merge findings on `#4282 PR 17` code, not F1-introduced
regressions. Normally we'd track as separate follow-up issues (mirror
of the #4325 / `channelInfo` decline). But:

- Both fixes are TINY (~25 LOC + ~2 LOC including comment); the bridge
  security fold-in commit `7bd66c6e8` set the precedent of folding in
  small same-branch issues when the cost-benefit favors closing them
  immediately.
- Same reviewer (wenshao via qwen-latest agent) — won't be confused
  by the scope expansion; in fact the original PR 17 commenter is
  also the one who'd review the follow-up issue's fix.
- Both fixes target `daemon_mode_b_main`-only paths (MCP restart route
  added by PR 17 lives on the integration branch).
- Saves opening 2 trivial follow-up issues that would just sit until
  someone picks them up.

#### Verification

- sdk-typescript: 424/424 tests pass (no test hardcoded the old
  300_000 default — only the constant declaration itself referenced it)
- cli acp-integration: 282/282 tests pass (no test exercised the
  exact whitespace-bearing disabled-tools scenario, so no test
  changes were strictly required; a regression test would belong in
  a separate test-coverage PR alongside the const.ts test gap from
  the #4297 unresolved-comment thread)
- typecheck clean across cli + sdk-typescript

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): wenshao review round 4 — 3 Suggestion fold-ins (#4319)

1. **bridge.ts:2270 stale line refs in `publishWorkspaceEvent` JSDoc**
   — comment said `permission_resolved at line 1717` (actual: line 682)
   and `broadcastWorkspaceEvent closure at ~line 2127` (actual: line
   1281). Line numbers drifted across the lift commits. Replaced both
   with function-name refs (`in resolvePending`, `declared above in
   this factory body`) that survive future edits.

2. **`ws.ts:613` opaque references in bridgeFileSystem.ts:20 +
   bridgeOptions.ts:267** — no `ws.ts` file exists in the repo; the
   ref came from an internal review thread on PR 18 that future
   readers can't locate. Replaced with a self-contained description
   ("post-PR-18 follow-up thread about BridgeClient's inline fs proxy
   bypassing WorkspaceFileSystem (originally raised in…

…BX9_p) (#4557)

* fix(serve): post-merge fixes for #4291 review (7 threads) (#4305)

* fix(serve): address qwen-latest review on merged #4291 (7 threads)

Seven post-merge findings from the qwen-latest review on #4291,
all real. Most are tightening fixes for issues introduced by the
earlier rounds of #4291 — the same security / DRY / observability
classes the original review surfaced, applied to surfaces that
weren't covered initially.

#1 (deviceFlow.ts:1179) — late-poll observer closure retained the
entire entry by reference (deviceCode/pkceVerifier BrandedSecrets +
cancelController) for the lifetime of the daemon if `provider.poll()`
never settled. Memory leak + indefinite secret retention. Destructure
the four fields the closure actually needs (deviceFlowId, providerId,
initiatorClientId, audit sink) so the entry is GC-eligible the
moment runPollTick returns.

#2 (server.ts) — `callerIsInitiator` was duplicated verbatim across
three locations: GET handler, toDeviceFlowStartResponseBody,
toDeviceFlowStateBody. The exact bug class #4291 was fixing was
"POST and GET diverged on the same redaction policy" — duplicating
the gate recreated the preconditions for divergence. Extracted to
shared `callerIsDeviceFlowInitiator(view, callerClientId)` helper
with the consolidated threat-model JSDoc. All three sites now call
the helper.

#3 (deviceFlow.ts:1110) — timeout callback constructed two separate
`DeviceFlowPollTimeoutError` instances (one for `signal.reason`, one
for the wrapper rejection). Each capture its own V8 stack trace,
and `signal.reason.stack` would diverge from the caught rejection's
stack — confusing for operators inspecting both. Build the sentinel
ONCE per timer fire and pass the same instance to both sites.

#4 (qwenDeviceFlowProvider.ts:273) — `Error.name` is a freely
assignable string property; a hostile fetch wrapper could set
`e.name = 'X\n[serve] FAKE LINE\x1b[31m'` to inject log lines or
ANSI sequences via the same vector we already closed for `oauthError`.
The non-OAuth catch path interpolated `${err.name}` raw. Apply the
same `sanitizeForStderr()` helper.

#5 (deviceFlow.ts:1551) — on the timeout path, `rawProviderError`
is undefined (deliberately, to skip the misleading
`provider.poll() threw (raw): ...` audit template), but that left
the audit hint field omitted entirely. Operators reading the
durable audit trail saw `errorKind: 'upstream_error'` with no signal
whether it was a hung IdP or a generic provider failure. Use
`result.hint` (which already carries the timeout-specific
`provider.poll() timed out after Nms; check IdP connectivity` text
built in the catch) so the audit matches the SSE event.

#6 (server.ts) — the `QWEN_SERVE_DEBUG` env-var check was inlined
in the GET route handler, duplicating the `isServeDebugMode()`
helper from `./debugMode.js` that workspaceAgents and
workspaceMemory already use. The inline copy also had a dead `?? ''`
fallback (the value is guaranteed truthy at that point per the
preceding check). Use the canonical helper.

#7 (deviceFlow.ts:1217) — late-rejection observer interpolated the
raw `lateErr.message` into the audit hint (truncated to 256 bytes,
but RFC 8628 `device_code` values fit comfortably in 256 bytes).
The provider's catch already uses the `name + length` redaction
pattern to prevent WAF-echoed `device_code`/PKCE leaks; the
registry layer was undoing that hardening because the same failure
settled late. Apply the same `name + length` pattern at the late-
rejection site.

Tests:
- Existing late-rejection test reseeded with a `device-code-secret-*`
  substring inside the long detail; hard-negative-asserts the seeded
  secret is absent from the audit + asserts the new
  `Error (message N bytes; raw suppressed)` shape.
- Existing poll-timeout test now also asserts: hint IS defined on
  the audit (not omitted), hint contains `'timed out after'` /
  `'check IdP connectivity'`, and `signal.reason instanceof
  DeviceFlowPollTimeoutError` (proves the single sentinel is
  shared between abort and reject).
- New `sanitizes control characters in attacker-controlled
  err.name` test in qwenDeviceFlowProvider.test.ts pins the round-4
  #4 fix with a hostile `e.name` containing `\n` + `\x1b[31m...`.

cli serve 702/702 (was 686, +16 — additional tests imported via
the acp-bridge package lift on main); sdk 421/421; typecheck clean
across all 4 workspaces; eslint --max-warnings 0 clean on touched
files.

Refs: #4175, #4255, #4291

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): address deepseek-v4-pro review on #4305 (4 threads)

Round-5 fold-in. Four findings from the deepseek-v4-pro review on
PR #4305 — all real, three are sister fixes for the same security
classes that #4305 already closed at adjacent surfaces.

#1 (deviceFlow.ts) — `pollTimedOut` race correctness. The flag was
set unconditionally inside the timer callback. If the provider
settled the wrapper at 29.9s, `finally` would call
`clearScheduled(pollTimer)` — but if the timer callback was already
queued for execution before the clear landed (a real possibility
in Node's event-loop ordering, even if not always observed in
practice), this branch could still run and incorrectly mark
`pollTimedOut`. Move the flag assignment to the catch block where
the settled cause is unambiguous via `instanceof
DeviceFlowPollTimeoutError`. New test pins the negative: provider
beats the timeout → no spurious `lost_late_poll_after_timeout`
audit even after ticking 2× the ceiling.

#2 (deviceFlow.ts) — late-rejection observer interpolated raw
`lateErr.name` into the audit hint without sanitization. Same
attacker-controlled vector closed at the provider layer for
`err.name` in round-4. Route through `sanitizeForStderr`.

#3 (deviceFlow.ts) — late-success observer interpolated
`latePollResult.kind` directly into the audit template. While the
typed shape is `'pending' | 'slow_down' | 'success' | 'error'`, a
non-conforming provider could return an arbitrary string. Same
log-injection vector. Route through `sanitizeForStderr`.

#4 (qwenDeviceFlowProvider.ts → deviceFlow.ts) —
`sanitizeForStderr` only stripped ASCII C0/C1 + DEL; bypass via
Unicode lookalikes:
  - U+2028/U+2029: LINE/PARAGRAPH SEPARATOR (newline-equivalent in
    most Unicode-aware terminals — most direct log-forging vector)
  - U+200B–U+200F: zero-width chars + LRM/RLM
  - U+202A–U+202E: bidirectional override controls
  - U+FEFF: BOM / ZWNBSP

A malicious IdP returning `slow_down
[serve] FAKE` in
`oauthError` would otherwise still forge log lines.

Architectural change: `sanitizeForStderr` was previously private to
`qwenDeviceFlowProvider.ts`. To address #2/#3, the registry layer
needs to call it too. Lifted into `deviceFlow.ts` (the foundation
module) and re-imported from the provider. Single source of truth;
the regex is now a module-level constant compiled once with explicit
`\uXXXX` escapes (via `String.raw` so the source is greppable, not
literal-Unicode-laden).

Tests:
- `does NOT attach late-poll observer when the provider beats the
  timeout` — N1 race regression
- `sanitizes hostile latePollResult.kind in late-observer audit` — N3
- `sanitizes hostile lateErr.name in late-rejection observer audit` — N2
- `sanitizes Unicode lookalike controls (U+2028 LINE SEPARATOR,
  bidi, ZWNBSP) in oauthError` — N4

cli serve 706/706 (was 702, +4 — all new round-5 tests); sdk
421/421; typecheck clean; eslint --max-warnings 0 clean on touched
files.

Refs: #4175, #4255, #4291, #4305

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): address gpt-5.5 + qwen-latest review on #4305 round-5 (5 threads)

Round-6 fold-in. Five findings split between maintainability,
security hardening, and a real defensive bug.

#1 (qwenDeviceFlowProvider.test.ts) — gpt-5.5: round-5 #4 test
embedded U+2028 / U+200E / U+FEFF as literal characters in source.
Invisible in GitHub diffs / most editors; the negative
`not.toContain('')` looked like an empty-string check. Rewrote
the payload + assertions to use named `\uXXXX`-bound constants.
Also added a companion test exercising U+2066–U+2069 (round-6 #5
below).

#2 (deviceFlow.ts) — qwen-latest: the late-poll observer's
`void tracked.then(...)` was missing a terminal `.catch(() => {})`.
A synchronous throw inside either handler (e.g., a misbehaving
`audit.record`: backpressure, malformed payload, sink out-of-disk)
would reject the derived promise unhandled. On Node 22's default
`--unhandled-rejections=throw`, that crashes the daemon. Added the
terminal `.catch(() => {})` matching the persist-tracker pattern.
New test injects a poison audit sink that throws specifically on
the `lost_late_poll_after_timeout` call; asserts `flushAsync()`
resolves cleanly.

#3 (deviceFlow.ts) — qwen-latest: the `case 'error'` audit-record
hint interpolated `rawProviderError` (raw `err.message`) without
`sanitizeForStderr`. Per ES2019+ `JSON.stringify` no longer escapes
U+2028/U+2029 — those would still forge log lines downstream
through file/stdout audit sinks. Apply the same sanitizer used on
every other provider-controlled audit path. New test pins a hostile
provider message containing U+2028 + ANSI escape and asserts
neither survives.

#4 (deviceFlow.ts) — qwen-latest: the round-5 #1 comment claimed
"`DeviceFlowPollTimeoutError` isn't exported as a public DeviceFlow
contract", but it IS `export class` (the test file constructs it
directly for fixtures). With `pollTimedOut = true` keyed solely on
`instanceof`, a future provider that imports + throws the class
would spoof the registry's "I caused the timeout" signal —
attaching a phantom late-poll observer.

Fix: introduce a runtime brand `_isRegistryTimeout: boolean` on the
class (default `false`) plus an internal-only
`makeRegistryPollTimeoutError(ms)` helper that sets the brand to
`true`. The brand is set ONLY at the registry's race-timer
construction site. Both gates updated:
  - `if (err instanceof X && err._isRegistryTimeout === true)` in
    the catch (for `pollTimedOut`)
  - `if (lateErr instanceof X && lateErr._isRegistryTimeout === true)`
    in the late-rejection self-filter

A provider-thrown brand-false instance now flows through the
generic provider-throw audit path — correctly auditing the misuse
rather than silently swallowing it. Repurposed the original "no
double-audit when registry's own DeviceFlowPollTimeoutError is
late-rejected" test (which was actually exercising the brand-false
path) into the inverted assertion: brand-false provider throw IS
audited as a real failure. Removed the orphaned old assertion; the
brand-true happy path is implicitly covered by the hanging-provider
test (which exercises the registry-built timeout end-to-end).

#5 (deviceFlow.ts) — qwen-latest: `sanitizeForStderr` regex covered
U+202A–U+202E (bidi embedding/override) but missed U+2066–U+2069
(LRI/RLI/FSI/PDI). These are the primary CVE-2021-42574
("Trojan Source") attack vectors — a hostile IdP swapping U+2066
for U+202D achieves the same visual reordering and would have
bypassed the round-5 filter entirely. Extended the regex range and
JSDoc; new test exercises U+2066/U+2068/U+2069 in `oauthError` and
asserts none survive while substantive ASCII parts remain.

cli serve 713/713 (was 710, +3 round-6 tests + the round-5 #4
rewrite + the round-6 #5 companion); typecheck clean across all 4
workspaces; eslint --max-warnings 0 clean on touched files.

Refs: #4175, #4255, #4291, #4305

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): replace literal U+2028 with explicit 
 escape in round-6 #3 test

PR #4312 review (Copilot): the round-6 #3 test (sanitizes
rawProviderError) regressed back to embedding a literal U+2028
character in source via `const U_2028 = ' '`. That's the same
maintainability anti-pattern round-6 #1 was fixing in the sister
test. Internal-consistency fix: switch to the explicit `
`
escape so the constant is greppable and reviewable in GitHub diffs.

Refs: #4291, #4305, #4312

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): post-merge P2 corrections from Codex review on #4282 (#4297)

* fix(serve): post-merge P2 corrections from Codex review on #4282

Follow-up to PR #4282 (Wave 4 PR 17) addressing four P2 issues
flagged by Codex's `/review` after the squash-merge to main:

P2-1 — Read the workspace context filename for init
  `qwen serve` parent never goes through `loadCliConfig`, so the
  process-global `getCurrentGeminiMdFilename()` stays on the default
  `QWEN.md` even when the workspace configures
  `context.fileName: 'AGENTS.md'`. `runQwenServe` now snapshots the
  workspace's merged setting at boot and forwards via
  `BridgeOptions.contextFilename`, so init writes the same file the
  ACP child reads.

P2-2 — Restart MCP servers with a fresh disabledTools snapshot
  `Config.disabledTools` was frozen at construction time;
  `setWorkspaceToolEnabled` only updated settings.json. The
  documented "toggle + restart" workflow re-registered just-disabled
  tools because rediscovery still saw the bootstrap snapshot. Added
  `Config.setDisabledTools()` plus a re-read at the ACP restart
  handler so `discoverMcpToolsForServer` honors the latest set.

P2-3 — Match the SDK timeout to the daemon's restart budget
  Bridge waits up to 300s for stdio MCP discovery; SDK helper used
  the client-wide 30s default and aborted valid slow restarts.
  Added a per-call `timeoutMs` plumbed through `fetchWithTimeout`,
  defaulting `restartMcpServer` to 5 minutes.

P2-4 — Reject symlinked parent directories before init writes
  `lstat(target)` only checked the final component; a symlinked
  parent (e.g. `docs -> /tmp` with `context.fileName:
  'docs/QWEN.md'`) would let `writeFile` follow the link and create
  / truncate outside `boundWorkspace`. Added
  `canonicalizeExistingAncestor` (walks up through ENOENT to the
  deepest extant ancestor, then `realpath`s) and verifies the
  canonical parent stays within the canonical workspace.

5 new tests (4 bridge / 2 SDK):
- contextFilename snapshot honored
- parent-symlink escape rejected
- nested real subdir accepted
- restartMcpServer survives 1.2s response with 1s default timeout
- restartMcpServer honors a 50ms caller override

Typecheck clean across cli / sdk-typescript / core.
1604/1604 unit tests pass.

* fix(serve): fold-in 1 — address 16:32:44-round review on #4282

Follow-up addressing the 8 unresolved review threads opened on PR
shipping in this same #4297; addresses correctness gaps + missing
test coverage that would otherwise let regressions ride into main.

Behavior fix:
- broadcastWorkspaceEvent gains a `skipSessionId` parameter; when
  `setSessionApprovalMode` runs with `persist:true`, the broadcast
  skips the requesting session so it doesn't receive the same
  `approval_mode_changed` event twice (once via session-scoped
  publish + once via broadcast). The SDK reducer's
  `approvalModeChangedCount` now increments by 1, not 2, on the
  requesting client (peers still see 1 via the broadcast).
  Addresses #3260501134.

Observability + posture:
- broadcastWorkspaceEvent now mirrors PR 16's publishWorkspaceEvent
  member: per-entry success/failure accounting + an "ALL buses
  dropped" stderr elevation. The previous local helper silently
  swallowed every publish failure. Addresses #3260501126.
- WorkspaceInitPathEscapeError + WorkspaceInitSymlinkError typed
  classes for the two boundary guards in initWorkspace, mapped to
  HTTP 400 by sendBridgeError. Previous generic `Error` fell
  through to the 500 handler, telling operators "daemon broken"
  when the actual fix was workspace-config correction. Addresses
  #3260501161.

Public surface symmetry:
- Re-export McpServerNotFoundError, McpServerRestartFailedError,
  WorkspaceInitPathEscapeError, WorkspaceInitSymlinkError from the
  serve barrel. External embeds matching these via `instanceof`
  no longer need deep imports. Addresses #3260501163.

Test coverage:
- restartMcpServer bridge tests (5): success + event broadcast,
  soft-skip + refused event, McpServerNotFoundError translation,
  McpServerRestartFailedError translation, originator clientId
  stamping. Addresses #3260501141.
- sendBridgeError mapping tests (4): McpServerNotFoundError → 404,
  McpServerRestartFailedError → 502, WorkspaceInitPathEscapeError
  → 400, WorkspaceInitSymlinkError → 400. Addresses #3260501148.
- initWorkspace boundary guard tests (2 added): symlink-at-target
  rejected, contextFilename '../outside.md' rejected. Addresses
  #3260501157.
- TrustGateError tests assert the typed class via `.toThrow(TrustGateError)`,
  not just message text. Addresses #3260501165.

Also updates the existing fold-in 4 S2 broadcast test to reflect
the new no-duplicate semantics on the requesting session.

Typecheck clean across cli / sdk-typescript / core.
1615/1615 unit tests pass.

* fix(serve): fold-in 2 — copilot + wenshao review on #4297

Round-2 reviewer adoption on the same PR:

Critical fixes:
- `restartMcpServer` JSDoc documents `timeoutMs: 0` as "disable the
  timeout entirely", but the `> 0` guard in `fetchWithTimeout`
  rejected `0` and silently fell back to the 30s client default.
  Loosened the guard to `>= 0` so `0` flows through to the
  no-timeout branch via the existing truthiness check; NaN /
  negative inputs still coerce to the client default. Addresses
  duplicate reports from copilot (#3260577538) and wenshao
  (#3260661833).
- TS2322 in the slow-fetch test stub: `resolveResponse` was typed
  against `import('undici-types').Response` but assigned a
  `(v: Response) => void`. Re-typed against the global `Response`
  throughout. Caught only by tsc runs that include the test
  files. Addresses #3260663072.

Test fidelity:
- Slow-fetch stub now observes `init.signal` and rejects on abort,
  so a regression that drops the per-call `timeoutMs` override
  will reliably fail the test instead of resolving after the
  timer fired (false-negative coverage). Addresses #3260577600.
- New test pinning the `timeoutMs: 0` semantics: 1ms client
  default + a stub that resolves after 50ms. Without the `>= 0`
  fix, the call would abort at 1ms; with it, the explicit
  `0` disables the timer and the call completes.

Bug fixes:
- `runQwenServe.contextFilenameForInit` previously called
  `String(arr[0])` on the array branch, producing a literal
  `"[object Object]"` filename for hand-edited bad data. Now
  validates each element with `typeof === 'string'` and falls
  back to `undefined` (so the bridge uses its
  `getCurrentGeminiMdFilename()` default) when no string is
  found. Addresses #3260577641.

Documentation drift:
- `Config.getDisabledTools()` JSDoc rewritten to describe the
  mutable-via-`setDisabledTools()` semantics introduced by P2-2,
  and the "registration-time only / no retroactive unregister"
  contract that pairs with it. Old comment claimed the set was
  frozen at construction. Addresses #3260577677.

Observability:
- `acpAgent` MCP-restart `loadSettings` failure now surfaces a
  stderr line naming the server + the underlying error, instead
  of silently swallowing it. The documented "toggle + restart"
  workflow used to break with zero diagnostic when settings.json
  was corrupted or unreadable. Addresses #3260663303.

Code organization:
- Moved `canonicalizeExistingAncestor` after `describeStatKind` so
  the latter's JSDoc is no longer orphaned (TypeScript only
  associates the last `/** ... */` block before a declaration).
  Addresses #3260668618.

Typecheck clean across cli / sdk-typescript / core.
1616/1616 unit tests pass.

* fix(serve): fold-in 3 — read merged scope on MCP restart refresh

Critical bug from wenshao review (#3260725526) on PR #4297:
the P2-2 acpAgent re-read narrowed `Config.disabledTools` to
`SettingScope.Workspace` alone, dropping User / System scope
entries. The bootstrap Config received `merged.tools?.disabled`
(union of all scopes), so user-level / system-level disables
worked at boot — but the first `mcp restart` would replace the
in-memory set with the workspace scope alone, silently re-enabling
any tool that was disabled at a higher scope but absent from the
workspace file.

The asymmetry vs. the persist-write path is deliberate and
documented:
- Reads (here): merged — match the bootstrap Config snapshot,
  preserve user/system policy.
- Writes (`runQwenServe.persistDisabledTools`): workspace scope —
  don't bake higher-scope entries into the workspace file
  (per-#4282 fold-in 1 H2 fix).

Two paths look alike but answer different questions.

Typecheck clean across cli / sdk-typescript / core.
1616/1616 unit tests pass.

* fix(test): fold-in 4 — wire timeoutMs:0 stub to init.signal

Critical follow-up from wenshao (#3260810242) on PR #4297:
the new `timeoutMs: 0` regression test (added in fold-in 2)
inherited the same flaw it was meant to prevent — the slow-fetch
stub didn't observe `init.signal`, so a regression that ignored
the `0` override would fire the AbortController at the 1ms client
default but the stub would keep the promise pending. The 50ms
`resolveResponse` would win, the test would still pass, and the
documented "0 disables timeout" contract would be unprotected.

Mirrored the listener pattern already used by the two sibling
tests in fold-in 2 — `init.signal.addEventListener('abort', () =>
reject(...))`. Now a regression that re-rejects `0` triggers the
abort, the stub rejects, the test fails.

8/8 restartMcpServer SDK tests pass; SDK typecheck clean.

* fix(serve): fold-in 5 — TOCTOU + setDisabledTools coverage

Two new critical reviews from wenshao on PR #4297:

C1 — TOCTOU between lstat and writeFile (#3260836305):
The `lstat(target)` symlink check and the subsequent `writeFile`
were two separate syscalls, leaving a race window where a local
attacker with workspace write access could substitute a symlink
between them. With `force: true`, `writeFile` would follow the
link and truncate an external target.

The `action === 'created'` path now uses `fs.open(target, 'wx')`
(O_WRONLY|O_CREAT|O_EXCL), which atomically refuses any
pre-existing inode (regular file, dir, OR symlink) at the target
path. EEXIST after the absence check most plausibly means a
race-created symlink, so we throw `WorkspaceInitSymlinkError(kind:
'target')` — same typed class the route maps to 400.

The `force: true` overwrite path retains the existing TOCTOU as a
documented limitation; closing it requires `O_NOFOLLOW`-aware open
which the post-PR18 `WorkspaceFileSystem` migration will provide.

C2 — P2-2 zero test coverage (#3260836302):
The `setDisabledTools` runtime sync was the only Wave-4 P2 fix
without a dedicated test. Added 5 Config-level tests:
- Initializes from `disabledTools` ConfigParameters
- Defaults to empty set when omitted
- `setDisabledTools` replaces the live snapshot
- Defensive copy: caller-set mutations don't leak into the live snapshot
- Accepts an empty set (clears live snapshot)

Plus a TOCTOU regression test in httpAcpBridge.test.ts that
spies fs.lstat / fs.readFile to simulate the race window:
pre-creates a symlink, makes lstat lie about it, asserts the
'wx' open catches the racing inode and throws the typed
`WorkspaceInitSymlinkError(kind: 'target')`.

1622/1622 unit tests pass; typecheck clean across cli /
sdk-typescript / core.

* fix(serve): fold-in 6 — count actual skips in broadcast alarm

DeepSeek review on #4297 (#3261079572):
`broadcastWorkspaceEvent` unconditionally subtracted 1 from the
`eligible` recipient count whenever `skipSessionId` was set, even
when the id matched zero live sessions (caller mistake, stale id,
or the matching session was just torn down between resolution and
broadcast). In a single-session workspace that's the difference
between `eligible = 0` (alarm suppressed) and `eligible = 1`
(alarm fires when the publish failed) — silently losing the
all-dropped breadcrumb the telemetry was meant to surface.

Today's call sites pass real session ids so the bug doesn't
manifest in practice, but the defensive shape is small: track
`skippedCount` inside the loop and subtract that, so the alarm
condition is self-consistent regardless of how the caller mis-uses
the param.

162/162 bridge tests pass; CLI typecheck clean.

* fix(serve): fold-in 7 — close overwrite TOCTOU, harden boot + diagnostics

Round-7 review on PR #4297. Three critical fixes + one suggestion
test, plus a regression test for the overwrite TOCTOU close.

C1 — force:true overwrite TOCTOU (#3262615446):
The fold-in 5 fix only closed the `'created'` action via 'wx';
the `'overwrote'` branch still used plain `fs.writeFile`, so a
local writer could swap the verified regular file to a symlink
between the lstat/readFile checks and the write and have the
forced overwrite truncate an external target. Switched to
`fs.open(target, O_WRONLY | O_TRUNC | O_NOFOLLOW)` — `O_NOFOLLOW`
makes open() fail with ELOOP on a symlink at the final component
even under race. ELOOP / ENOENT (race-deleted) translate to
`WorkspaceInitSymlinkError(kind: 'target')` so the route still
maps to a structured 400 instead of a generic 500.

C2 — settings.json corrupt blocks daemon boot (#3262625091):
`loadSettings(boundWorkspace)` at boot had no try/catch — a
corrupted, malformed, or temporarily unreadable settings file
threw synchronously and prevented daemon startup. Pre-PR this
never happened because settings were read lazily inside request
handlers. Wrapped in try/catch with stderr fallback so the daemon
keeps booting (with the bridge's default context filename) when
the file is broken.

C3 — malformed `tools.disabled` clears policy silently (#3262625101):
When `merged.tools?.disabled` is present but not an array
(boolean / string / object from a hand-edited settings.json), the
ternary `Array.isArray(...) ? ... : []` substituted an empty list
without firing the surrounding catch block. After an MCP restart
every disabled tool would silently re-register. Added an explicit
`!Array.isArray && !== undefined` check that stderr-logs the
malformed type before clearing — operators see the
misconfiguration instead of a stealth re-enable.

S1 — contextFilename extraction tested (#3262690842):
Lifted the inline `firstStringInArray` + branching into an
exported `extractContextFilename(value: unknown)` helper and
added `runQwenServe.test.ts` with 5 tests covering the four
branches the suggestion called out: non-empty string, array with
strings, array with no strings, non-string non-array.

Plus a TOCTOU regression test for the overwrite path that
verifies `O_NOFOLLOW` returns `WorkspaceInitSymlinkError(kind:
'target')` when the file is race-substituted with a symlink
behind the lstat/readFile mocks.

S2 (acpAgent restart-handler integration test #3262690845) is
deferred — Config-level coverage of `setDisabledTools` already
locks the load-bearing surface (5 tests in fold-in 5), and
adding a full acpAgent integration test requires heavy ext-method
plumbing. The new C3 stderr diagnostic plus existing tests give
us the regression signal we need without that scaffolding.

1627/1627 unit tests pass; typecheck clean across cli /
sdk-typescript / core / acp-bridge.

* fix(serve): fold-in 8 — split ELOOP / ENOENT diagnostic in overwrite path

qwen-latest review on PR #4297 (#3262861754):
The fold-in 7 ELOOP/ENOENT branch shared one error message that
said "swapped to a symlink." That's accurate for ELOOP (genuine
O_NOFOLLOW rejection — likely an attack race) but misleading for
ENOENT in the overwrite path: there `readFile` just succeeded
proving the file existed, so ENOENT means the file was DELETED
between the content check and the open — a benign race with a
concurrent writer (git checkout, editor save, lockfile rename),
NOT a symlink swap. An operator seeing the symlink language for
a benign delete would `ls -la`, see no symlink, and waste time
hunting an attack that didn't happen.

Split into two messages:
- ELOOP: "swapped to a symlink between the content check and the
  overwrite — refusing to follow it"
- ENOENT: "deleted between the content check and the overwrite
  (likely a concurrent writer) — refusing to recreate blindly"

Both still surface as `WorkspaceInitSymlinkError(kind: 'target')`
so the route maps to a structured 400; the class doubles as the
workspace-init race-condition bucket with kind='target' meaning
"target inode misbehaved at write time" generally.

Updated the existing fold-in 7 TOCTOU test to assert the ELOOP
message specifically, and added a new ENOENT race-delete test
that mocks lstat/readFile to land on the overwrote action against
a non-existent path — verifies the message says "deleted" and
NOT "swapped to a symlink."

170/170 bridge tests pass; CLI typecheck clean.

* fix(serve): fold-in 9 — route MCP restart through registry cleanup wrapper

gpt-5.5 critical review on PR #4297 (#3263088414):

The fold-in 5 P2-2 fix refreshed `Config.disabledTools` from merged
settings, but then called `manager.discoverMcpToolsForServer()`
directly — bypassing the `ToolRegistry.discoverToolsForServer`
wrapper that PURGES the server's existing `DiscoveredMCPTool`
entries (and `revealedDeferred` markers) plus its prompts before
rediscovery. Without the cleanup, `registerTool` only consulted
the refreshed `disabledTools` set for NEWLY-discovered tools —
entries already in the registry from the prior MCP boot kept
serving requests. Net effect: toggle-disable-then-restart
silently left the disabled tool live, breaking the documented
"toggle + restart" workflow that P2-2 was meant to fix.

Routed through `toolRegistry.discoverToolsForServer(serverName)`
which:
1. Removes existing `DiscoveredMCPTool` entries for this server
2. Drops their `revealedDeferred` reveal state
3. Removes the server's prompts via `removePromptsByServer`
4. THEN delegates to `manager.discoverMcpToolsForServer` for the
   actual reconnect + rediscover

The pre-discovery budget / in-flight checks still go through the
`manager` reference (which is the same object the registry
wrapper would forward to) — so soft-skip semantics for
`budget_would_exceed`, `in_flight`, `disabled` are preserved.

CLI typecheck clean; 403/403 server + bridge tests pass.

* fix(serve): fold-in 10 — qwen-latest 05:45-round review on #4297

5 review threads from qwen-latest's late round on PR #4297 (now closed
in favor of #4313 against `daemon_mode_b_main`). 1 critical + 4
suggestions, all adopted.

C1 — extractContextFilename / getCurrentGeminiMdFilename divergence
(#3263954685): with `context.fileName: ['  ', 'AGENTS.md']`, the
daemon parent's `extractContextFilename` (which skips empty entries)
wrote `AGENTS.md`, but the ACP child's `getCurrentGeminiMdFilename`
(which returned `arr[0]` unconditionally) read `''`. The init'd file
was orphaned. Aligned `getCurrentGeminiMdFilename` to skip empty
entries with the same semantics, falling back to
`DEFAULT_CONTEXT_FILENAME` when all entries are empty.

S2 — WorkspaceInitSymlinkError reused for non-symlink races
(#3263954690): the EEXIST race-create and ENOENT race-delete cases
were surfacing as `code: 'workspace_init_symlink'`, misleading
operators into hunting symlink attacks for benign concurrent-
modification windows. Split into a sibling `WorkspaceInitRaceError`
class (`kind: 'eexist' | 'enoent'`, HTTP code
`workspace_init_race`). The genuine symlink class stays for ELOOP,
lstat-detected target symlinks, and parent-realpath escapes.

S3 — fsConstants.O_NOFOLLOW defensive `?? 0` (#3263954697): matches
the existing codebase convention in
`core/src/utils/{sessionStorageUtils,gitDiff}.ts` and
`cli/src/ui/utils/customBanner.ts`. Functionally a no-op (JS
bitwise coerces undefined to 0) but consistent.

S5 — Parent-directory TOCTOU still open (#3263954707): O_NOFOLLOW
only protects the final path component; a local writer could swap
a real parent dir for a symlink between
`canonicalizeExistingAncestor` and `fs.open`. Added
`verifyParentWithinWorkspace` post-open helper that re-realpaths
`path.dirname(target)` and refuses with
`WorkspaceInitSymlinkError(kind: 'parent')` if the parent moved.
On the create path (where we just opened with `'wx'`), the failure
also unlinks the file we just made best-effort. Residual race
window narrowed from "between pre-check and open" to "between
post-open realpath and writeFile" — sub-millisecond, documented as
accepted Stage-1 trust posture.

S4 — broadcastWorkspaceEvent vs publishWorkspaceEvent stale comment
(#3263954688): the "now removed" comment was inaccurate (5 call
sites still use the closure). Replaced with an accurate
description of why both coexist (factory closure can't `this`-call
proxy member; closure also takes `skipSessionId` for persisted
approval-mode mirror) and a TODO marker for future helper extraction.

Two existing tests updated to assert the new `WorkspaceInitRaceError`
class for EEXIST / ENOENT scenarios (the symlink-class assertions
are preserved for ELOOP / lstat / parent cases).

1759/1759 unit tests pass; typecheck clean across all 4 packages.

* feat(acp-bridge): F1 — acp-bridge package self-sufficiency (#4175 mechanical lift + BridgeFileSystem seam) (#4319)

* refactor(acp-bridge): lift defaultSpawnChannelFactory to acp-bridge/spawnChannel (#4175 F1 step 1)

First mechanical lift of #4175 F1 (acp-bridge package self-sufficiency).
Moves the production spawn factory + its `killChild` helper +
`SCRUBBED_CHILD_ENV_KEYS` denylist + `KILL_HARD_DEADLINE_MS` constant
from `cli/src/serve/httpAcpBridge.ts` (~283 lines) to
`@qwen-code/acp-bridge/spawnChannel`. This unblocks
`channels/base/AcpBridge.ts` and `vscode-ide-companion`'s
acpConnection from each reimplementing the child lifecycle — they can
now consume the same primitive.

Backward compatible: `cli/src/serve/httpAcpBridge.ts` imports the
lifted factory and re-exports it, so existing references in
`cli/src/serve/index.ts:90` and the factory's own internal usage
(`opts.channelFactory ?? defaultSpawnChannelFactory`) keep resolving.
Bridge tests that mock `defaultSpawnChannelFactory` via
`BridgeOptions.channelFactory` are unaffected.

Side cleanups: drops `spawn` / `ChildProcess` / `Readable` / `Writable`
/ `ndJsonStream` / `MissingCliEntryError` imports from
httpAcpBridge.ts (all only used by the lifted spawn factory).

- 44/44 acp-bridge tests pass
- 174/174 cli httpAcpBridge tests pass
- typecheck clean across acp-bridge + cli

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* refactor(acp-bridge): lift BridgeClient + permission types to acp-bridge/bridgeClient (#4175 F1 step 2)

Second mechanical lift of #4175 F1 (acp-bridge package self-sufficiency).
Moves `BridgeClient` class (~700 LOC) + `PendingPermission` interface +
`PermissionResolutionRecord` interface + `MAX_RESOLVED_PERMISSION_RECORDS`
constant + early-event capacity constants + `describeStatKind` and
`sliceLineRange` helpers from `cli/src/serve/httpAcpBridge.ts` to
`@qwen-code/acp-bridge/bridgeClient`.

Design choice for SessionEntry boundary: introduce a minimal
`BridgeClientSessionEntry` interface in bridgeClient.ts with only the
four fields BridgeClient actually reads from the factory's richer
`SessionEntry` (`sessionId`, `events`, `pendingPermissionIds`,
`activePromptOriginatorClientId`). The factory's `SessionEntry`
structurally satisfies it — TypeScript's structural typing enforces
the match at the `resolveEntry` callback signature, so no explicit
conversion is required and the bridge package stays free of daemon-host
session-bookkeeping types.

Cross-package writeStderrLine handling: inline the 3-line helper in
bridgeClient.ts (mirrors the spawnChannel.ts pattern from F1 step 1)
so acp-bridge has no reverse dependency on `cli/src/utils/stdioHelpers`.

httpAcpBridge.ts shrinks from 4406 LOC to 3647 LOC (-759 lines).
Removed ACP SDK imports that only BridgeClient consumed: `Client`,
`RequestPermissionRequest`, `WriteTextFileRequest`,
`WriteTextFileResponse`, `ReadTextFileRequest`, `ReadTextFileResponse`,
`SessionNotification`. Kept the ones the factory still uses
(`CancelNotification`, `PromptRequest`, `RequestPermissionResponse`,
`SetSessionModelRequest`, `SetSessionModelResponse`).

Backward compatible: httpAcpBridge.ts re-exports `BridgeClient`,
`BridgeClientSessionEntry`, `PendingPermission`,
`PermissionResolutionRecord`, and `MAX_RESOLVED_PERMISSION_RECORDS` so
the `ChannelInfo.client: BridgeClient` field declaration below + any
embedder reaching into these types keep resolving.

- 44/44 acp-bridge tests pass
- 174/174 cli httpAcpBridge tests pass
- 229/229 cli server tests pass
- typecheck clean across acp-bridge + cli

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* refactor(acp-bridge): lift createHttpAcpBridge factory to acp-bridge/bridge (#4175 F1 step 3)

Third + final mechanical lift of #4175 F1 (acp-bridge package
self-sufficiency). Moves the `createHttpAcpBridge` factory closure
(~3000 LOC) + `ChannelInfo` + `SessionEntry` interfaces + factory-only
helpers (`canonicalizeExistingAncestor`, `verifyParentWithinWorkspace`,
`withTimeout`, `isServeDebugLoggingEnabled`, `writeServeDebugLine`,
`hasControlCharacter`) + factory constants (`DEFAULT_INIT_TIMEOUT_MS`,
`MCP_RESTART_TIMEOUT_MS`, `DEFAULT_MAX_SESSIONS`, `MAX_EVENT_RING_SIZE`,
`DEFAULT_PERMISSION_TIMEOUT_MS`, `DEFAULT_MAX_PENDING_PER_SESSION`,
`MAX_DISPLAY_NAME_LENGTH`) from `cli/src/serve/httpAcpBridge.ts` to
`@qwen-code/acp-bridge/bridge`.

`cli/src/serve/httpAcpBridge.ts` shrinks from 3647 LOC to 97 LOC — a
pure re-export shim that preserves every existing relative import
path (`./httpAcpBridge.js`) so `server.ts`, `runQwenServe.ts`,
`workspaceAgents.ts`, `workspaceMemory.ts`, `index.ts`, plus the bridge
test suite, keep resolving without any call-site changes.

The new `bridge.ts` reuses what was already in acp-bridge (errors,
types, options, status helpers, channel types, event bus, workspace
paths) via local relative imports — no reverse dependency on `cli`.
`writeStderrLine` is inlined at the top of `bridge.ts` (same pattern as
`spawnChannel.ts` + `bridgeClient.ts` from F1 steps 1-2) so the
package self-contained promise holds.

Cumulative F1 impact across the 3 mechanical lift steps:
- httpAcpBridge.ts: 4682 LOC → 97 LOC (-4585 lines; the original file
  was 98% bridge core, 2% backward-compat re-exports)
- 3 new files in acp-bridge: spawnChannel.ts (~270 LOC), bridgeClient.ts
  (~745 LOC), bridge.ts (~3515 LOC)
- All daemon-host concerns (env snapshot, daemon preflight cells)
  remain in `cli/src/serve/daemonStatusProvider.ts` and reach the
  bridge through the `BridgeOptions.statusProvider` seam frozen by
  PR 22b/2.

- 735/735 cli serve tests pass across 17 files
- 174/174 cli httpAcpBridge tests pass
- 44/44 acp-bridge tests pass
- typecheck clean across acp-bridge + cli

`packages/cli/src/serve/httpAcpBridge.test.ts` (~6600 LOC) is
intentionally NOT moved in this commit — it currently imports
`createHttpAcpBridge` / `defaultSpawnChannelFactory` / `BridgeClient`
via the cli shim and keeps passing without changes. Moving it to
`acp-bridge/src/bridge.test.ts` is a follow-up worth tracking
separately so the production-code lift can land + be reviewed cleanly.

The `BridgeFileSystem` injection seam (originally bundled into F1 as
the 22b' scope) is also deferred to a follow-up so the mechanical lift
stays mechanical — design + implementation of the fs injection is its
own discussion.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* feat(acp-bridge): add BridgeFileSystem injection seam (#4175 F1 step 5, 22b' scope)

Adds the `BridgeFileSystem` injection seam originally scoped as #4175
22b'. When a `BridgeFileSystem` is wired through
`BridgeOptions.fileSystem`, `BridgeClient.readTextFile` and
`BridgeClient.writeTextFile` delegate to it instead of running their
inline `fs.realpath` / `fs.writeFile` / `fs.readFile` proxy.

This unblocks production `qwen serve` plumbing PR 18's
`WorkspaceFileSystem` (TOCTOU guards, symlink-substitution checks,
trust gate, `.gitignore`, audit hooks) into the ACP fs methods —
closing the `ws.ts:613` follow-up thread that has been tracked since
PR 18 landed. The serve-side adapter that wraps `WorkspaceFileSystem`
+ the `runQwenServe` wiring are intentionally split into the
immediate-follow-up so this PR stays focused on the seam design.

Backward compatible: `fileSystem` is optional on `BridgeOptions`.
Tests, Mode A in-process consumers, channels (`packages/channels/base/
AcpBridge.ts`), and the VSCode IDE companion all keep working
unchanged — they omit the field and `BridgeClient` falls through to
the inline proxy that has been the Stage 1 default since #3889.

API:
- `BridgeFileSystem.readText(params: ReadTextFileRequest):
  Promise<ReadTextFileResponse>`
- `BridgeFileSystem.writeText(params: WriteTextFileRequest):
  Promise<WriteTextFileResponse>`

The interface mirrors ACP SDK request/response types directly so the
adapter does the minimum amount of translation (`{ path, content }`
↔ `WorkspaceFileSystem`'s `ResolvedPath` brand types + options bag).

- 735/735 cli serve tests pass (inline fallback path preserved)
- 44/44 acp-bridge tests pass
- typecheck + eslint clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): catch README + stale source comments up to F1 lift

Self-review fold-in: post-F1 the package README still said "PR 22a"
and listed `BridgeClient` / `createHttpAcpBridge` /
`defaultSpawnChannelFactory` under "What's not here yet" — both
contradicted by this PR. Updated:

- README lift-history table now shows PR 22a / 22b/1 / 22b/2 as
  merged and F1 (this PR) as the slice that closes the bridge core
  + adds `BridgeFileSystem`. F3 PR 24 row aligned to the
  feature-cohesive plan.
- "What's here today" now documents `spawnChannel`, `bridgeClient`,
  `bridge`, `bridgeFileSystem` modules.
- "What's not here yet" section removed (its 2 bullets are both
  resolved by F1).
- Subpath import list updated to enumerate all 14 subpaths.
- Backward-compat section updated to call out the 97-line shim and
  the 6 consuming files that still import via `./httpAcpBridge.js`.

Source-comment line-number drift:
- `channel.ts:12` no longer claims `defaultSpawnChannelFactory` is
  "still in cli/src/serve/httpAcpBridge.ts" — points to the lifted
  location.
- `permission.ts:33` + `permission.ts:45` no longer reference
  `httpAcpBridge.ts:1096-1106` / `httpAcpBridge.ts:1003` (file is
  now 97 lines after F1). Updated to point at the structurally-
  equivalent locations inside the lifted `bridgeClient.ts`.
- `permission.ts:7` no longer says first-responder still lives in
  `cli/src/serve/httpAcpBridge.ts` — points at the bridgeClient.ts
  location.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): adopt 3 Copilot review comments on F1 doc accuracy

Folds in 3 of 4 Copilot inline comments from #4319 review:

1. `bridgeClient.ts` writeTextFile preserveMode comment said "fall
   through to umask defaults" for new files, but the code passes
   `mode: preserveMode?.mode ?? 0o600` to `fs.writeFile`. Updated the
   "BkwQW" comment + the inner catch-block comment to clarify that
   new files actually get the `0o600` default applied at writeFile
   time (NOT umask defaults — the explicit `mode` arg bypasses umask
   for atomicity per the `Blehd` comment block).

2. `bridgeFileSystem.ts` JSDoc referenced
   `cli/src/serve/bridgeFileSystemAdapter.ts` as if the file exists,
   but it's deferred to the immediate F1 follow-up PR. Reworded as
   "the immediate follow-up PR will land a serve-side adapter" so
   reviewers don't grep for a non-existent file.

3. `bridgeOptions.ts` `fileSystem` field JSDoc had the same wording
   issue ("Production `qwen serve` wires this to..."). Same fix — now
   says "The immediate F1 follow-up will land a serve-side adapter"
   so the deferred state is obvious.

Declined from this review round:

- Copilot inline #1 (`spawnChannel.ts:155` stderr forwarder drops
  empty lines): pre-existing behavior since #3889. F1 lifted verbatim
  — not a regression introduced here. Out of scope for a lift PR.
- github-actions bot summary: most items are pre-existing notes
  (TOCTOU residual race, SCRUBBED_CHILD_ENV_KEYS allowlist concern,
  sliceLineRange benchmark threshold) on code the F1 lift moved
  verbatim. One ("httpAcpBridge.ts still has ~3700 LOC") is a false
  positive — the file is 97 LOC after F1. Others are cosmetic
  refactors (extract FIXME to tracking issue, ARCHITECTURE_DECISIONS
  doc system, deprecation timeline) that aren't worth churning the
  lift PR over.

- 44/44 acp-bridge tests pass
- typecheck clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): tighten BridgeFileSystem contract + re-export type from shim

Self-review + code-reviewer agent fold-in, two changes:

1. `cli/src/serve/httpAcpBridge.ts` shim now re-exports
   `BridgeFileSystem` from `@qwen-code/acp-bridge/bridgeFileSystem`
   so the immediate F1 follow-up adapter (in `cli/src/serve/`)
   can import it via the established `./httpAcpBridge.js` path
   like every other daemon-side bridge import does. Without this
   the adapter would need to deep-import from acp-bridge while
   every other serve file goes through the shim — inconsistent.

2. `BridgeFileSystem.readText` + `writeText` JSDoc now spells out
   the two defensive gates the inline proxy carried (non-regular-
   file rejection + 100 MiB buffered-size cap for reads;
   write-then-rename atomicity + dangling-symlink walk-through +
   mode preservation + `0o600` new-file default for writes). When
   a `BridgeFileSystem` is injected, the inline path is FULLY
   bypassed — without the contract spelled out, a future adapter
   author could silently drop the `/dev/zero` / 500 MB log RSS
   defenses the inline path established.

Note on F1 CI: this PR targets `daemon_mode_b_main` but the
`.github/workflows/ci.yml` `pull_request` trigger is scoped to
`branches: main / release/**`, so the main CI workflow (Lint /
Test on Linux/macOS/Windows / CodeQL) does NOT run on this PR.
This is a by-design side effect of the new feature-cohesive
branching strategy — `daemon_mode_b_main → main` periodic merges
will trigger the full CI matrix, providing safety net coverage
before any F-series work lands on `main`. Locally verified:
- 174/174 cli httpAcpBridge tests pass
- 44/44 acp-bridge tests pass
- 735/735 cli serve tests pass
- typecheck clean across acp-bridge + cli

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* test(acp-bridge): cover BridgeFileSystem injection seam + extract shared writeStderrLine (#4319 wenshao review)

Folds in wenshao review on #4319:

1. **[Critical]** zero test coverage for the F1 step 5 `BridgeFileSystem`
   delegation branches in `BridgeClient.writeTextFile` /
   `BridgeClient.readTextFile` and the factory's
   `opts.fileSystem` → constructor positional-arg forwarding.

   New `packages/acp-bridge/src/bridgeClient.test.ts` adds 6 tests
   covering:
   - writeTextFile delegates to injected fileSystem.writeText (inline
     proxy fully bypassed; `fakeFs.writeText` called with the original
     params; `readText` mock not invoked)
   - writeTextFile invalid-path call succeeds purely via the mock
     when fileSystem is injected (proof that the inline `fs.realpath`
     path doesn't run)
   - readTextFile delegates to injected fileSystem.readText
   - readTextFile propagates injection errors to the caller
   - inline-fallback regression guard: write actually hits disk via
     the inline proxy when fileSystem is omitted (real tmp file
     round-trip)
   - same for read

   Why these matter: the 7-arg `BridgeClient` constructor places
   `fileSystem` at the tail as optional. A reordering — or dropping
   the arg from `bridge.ts` factory's `new BridgeClient(..., opts.fileSystem)`
   call — would silently bypass the adapter in production and the
   inline `fs.writeFile` raw-path would run with no audit / trust /
   TOCTOU coverage. The delegation tests would catch that because
   the mock fileSystem would never be invoked.

2. **[Suggestion]** `writeStderrLine` was defined identically in
   `bridge.ts:117` and `bridgeClient.ts:30` (22 call sites across the
   two files). Both consumers live in the SAME `@qwen-code/acp-bridge`
   package, so the original "no reverse-dep on cli" justification
   doesn't apply within the package. Extracted to
   `packages/acp-bridge/src/internal/stderrLine.ts` — a single source
   of truth that future behavior changes (timestamp prefix, log
   level, structured field) can edit once. `internal/` subpath is
   intentionally not in `package.json`'s `exports`, keeping the
   helper package-private. `spawnChannel.ts` deliberately does NOT
   consume it (its stderr writes use `process.stderr.write(prefix +
   line + '\n')` directly because each line carries its own
   `[serve pid=… cwd=…]` line prefix).

- 6/6 new BridgeFileSystem-seam tests pass
- 50/50 acp-bridge total (44 existing + 6 new)
- 174/174 cli httpAcpBridge tests pass (no regression from refactor)
- typecheck + eslint clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* test(acp-bridge): cover defaultSpawnChannelFactory env scrubbing + fix bridge.ts comment refs (#4319 wenshao round 2)

Folds in wenshao review on #4319 round 2 — 1 Critical + 2 Suggestions:

1. **[Critical] spawnChannel.ts has 0 unit tests, security-critical
   paths untested.** Now that `defaultSpawnChannelFactory` is a public
   export of `@qwen-code/acp-bridge`, channels + IDE consumers can't
   rely on cli-package integration tests for env-scrubbing guarantees.

   Refactored the inline env-scrubbing logic into a pure exported
   helper `scrubChildEnv(source, scrubbed, overrides)`. Behavior is
   byte-identical to the pre-extraction inline implementation; the
   factory body now reads:

       const childEnv = scrubChildEnv(
         process.env, SCRUBBED_CHILD_ENV_KEYS, childEnvOverrides);

   Added `packages/acp-bridge/src/spawnChannel.test.ts` with 12 tests
   covering:
   - shallow-clone (no aliasing into live process.env)
   - QWEN_SERVER_TOKEN stripping
   - non-scrubbed vars pass through
   - override-add a new key
   - override-replace an existing key
   - override with undefined deletes the key (PR 14 fix #4247 wenshao R5)
   - override CANNOT re-introduce a scrubbed key (defense in depth)
   - override CANNOT undo the scrub by setting undefined for a scrubbed key
   - override-apply-after-scrub ordering invariant
   - empty overrides equals no overrides
   - multi-key scrub for forward-compat (the WARNING comment on
     SCRUBBED_CHILD_ENV_KEYS anticipates a future sandboxed-agent
     mode expanding the denylist; this verifies the loop already
     handles that)

   The killChild SIGTERM→SIGKILL escalation + STDERR_LINE_CAP_CHARS
   truncation are NOT covered yet — they require either real child
   processes or extensive node:child_process mocking; both are
   orthogonal to the env-scrubbing security guarantees wenshao
   explicitly called out, and can land as a follow-up if anyone
   wants the full surface tested.

2. **[Suggestion] bridge.ts comments referenced a "consolidated re-
   export block earlier in this file" that doesn't exist in acp-bridge
   (only in the cli shim).** Fixed both occurrences (~line 292, ~line
   310) to point at the actual local import + the package barrel
   re-export.

3. **[Suggestion] bridge.ts canonicalizeWorkspace re-export comment
   referenced `./fs/paths.ts`.** Updated to mention the full lift
   chain: extracted to `cli/src/serve/fs/paths.ts` in PR 18, then
   lifted here to `./workspacePaths.ts` in PR 22b/1.

- 12/12 new spawn env-scrub tests pass
- 62/62 acp-bridge total (50 existing + 12 new spawn)
- 174/174 cli httpAcpBridge tests still pass (the factory's inline
  env-scrubbing refactor preserves byte-identical behavior)
- typecheck + eslint clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): fix 14-arg→7-arg typo in test docstring + simplify canonicalizeWorkspace re-export doc (#4319 wenshao round 3)

Folds in 2 of 3 wenshao Suggestions from #4319 round 3:

1. `bridgeClient.test.ts:20` JSDoc said "the 14-arg constructor's
   positional slot" — typo I introduced when writing the test in
   `fbc92bccf`. The same docstring correctly says "the constructor
   takes 7 positional args" at line 25. Updated to "7-arg".

2. `bridge.ts:3461` `canonicalizeWorkspace` re-export JSDoc no longer
   references the historical `cli/src/serve/fs/paths.ts` location.
   Reads cleaner as a present-tense pointer to `./workspacePaths.ts`
   (where the implementation actually lives now post-PR 22b/1).
   Git history covers the lift chain; the docstring should describe
   current state.

DECLINED + tracked separately:

- **[Critical]** `closeSession` + `killSession` use module-scoped
  `channelInfo` instead of `channelInfoForEntry(entry)` — channel-
  overlap edge case can kill the wrong channel. Wenshao explicitly
  notes "pre-existing bug preserved by the lift" — F1's mechanical-
  lift scope shouldn't carry behavior fixes, and the fix needs a
  channel-overlap regression test to land safely. Tracked as #4325.

- 62/62 acp-bridge tests pass (no regression from doc tweaks)
- typecheck + eslint clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): polish from second-pass self-review (cross-platform test + package metadata + dead tombstones)

Five small adoptions from a second-pass code-reviewer agent review on
F1 (no new external comments — pre-emptive cleanup before reviewer
returns):

1. **`bridge.ts:290-313`** — deleted two standalone "InvalidPermission
   OptionError / WorkspaceInit* / McpServer* lifted to bridgeErrors"
   tombstone comments. Pre-22b they were load-bearing (explained why
   the class wasn't `class`-defined inline at that file location).
   Post-F1 the symbols are imported at the top of the file and the
   comments sit between unrelated code (`writeServeDebugLine` /
   `MAX_DISPLAY_NAME_LENGTH` / `DEFAULT_INIT_TIMEOUT_MS`) with no
   anchor. Dead doc — removed.

2. **`README.md`** — `spawnChannel` entry now lists `scrubChildEnv`
   alongside `defaultSpawnChannelFactory` + `killChild` +
   `SCRUBBED_CHILD_ENV_KEYS`. Channels / VSCode IDE consume the
   package barrel so the helper should be visible in the inventory.

3. **`package.json:description`** — refreshed from the PR 22a wording
   ("EventBus, AcpChannel, in-memory channel, PermissionMediator
   interface") to include F1 additions (`createHttpAcpBridge` /
   `BridgeClient` / `defaultSpawnChannelFactory` / `BridgeFileSystem`).
   Visible on `npm view`-style tooling + IDE hover so worth keeping
   current.

4. **`bridgeClient.test.ts:92-115`** — swapped `/proc/no-such-file`
   for `/this/dir/never/exists/file.txt` and reworded the comment.
   `/proc/` is Linux-only; on macOS / Windows the inline proxy's
   dangling-symlink fallback would write through to a path under
   root rather than failing. Test passed regardless (mock assertion,
   not real disk) but the comment overstated portability.

5. **`spawnChannel.test.ts:36`** — added a comment block explaining
   why the test deliberately hand-rolls the SCRUBBED set instead of
   importing the production `SCRUBBED_CHILD_ENV_KEYS`. The
   decoupling is intentional (pure-function parameterized test +
   forward-guard for future denylist expansion) but a naive reader
   would think it's an oversight.

- 62/62 acp-bridge tests pass
- 174/174 cli httpAcpBridge.test.ts pass
- typecheck + eslint + pre-commit hooks clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(acp-bridge): bridge.ts security fold-in from #4297 review (3 issues)

Folds 3 unresolved review comments from the post-merge thread on #4297
(wenshao via qwen-latest agent) into F1 (#4319). All 3 touch
`acp-bridge/src/bridge.ts` — the same file F1 already moves the lifted
factory into — so consolidating here saves opening a separate
follow-up PR and keeps the security narrative in one reviewable
commit. The 2 cross-package fixes (`core/src/memory/const.ts` test
gap + `cli/src/serve/runQwenServe.ts` malformed-context fallback)
will land as their own small PRs after F1 merges.

#### Fix 1 (wenshao Critical, #4297 thread): `fs.unlink(target)`
arbitrary-file-deletion primitive in `verifyParentWithinWorkspace`
'create'-cleanup

After `fs.open(target, 'wx')` creates the empty file at the real
parent, an attacker with local workspace write access can swap the
parent directory for a symlink (`docs/` → `/etc`). The cleanup's
`fs.unlink(target)` re-resolves the TEXTUAL path through the
attacker's freshly-planted parent symlink, deleting whatever file
exists at the external location.

Fix: drop the `fs.unlink(target)` line. The 0-byte file at the
pre-race location is harmless (0 bytes, inside the workspace we'd
already verified) — leaving it over deleting an arbitrary external
file is the right safety trade. Comment block explains the
reasoning so future maintainers don't re-introduce the unlink.

#### Fix 2 (wenshao Critical): `O_TRUNC` arbitrary-file-truncation
primitive in workspace-init 'overwrite' branch

`O_TRUNC` causes the kernel to truncate the file to zero bytes AT
`open(2)` SYSCALL TIME — strictly before `verifyParentWithinWorkspace`
runs. A parent-symlink TOCTOU race between
`canonicalizeExistingAncestor` and this `open()` zeros the file at
the attacker-redirected location (arbitrary-file-truncation
primitive against any file the daemon UID can open). The pre-fix
code's own comment on `verifyParentWithinWorkspace` acknowledged
this as "Acceptable residual posture for the Stage-1 trust model";
wenshao pushed back that arbitrary-file-zeroing exceeds the
Stage-1 trust budget.

Fix: drop `O_TRUNC` from the open flags. Truncation moves to AFTER
`verifyParentWithinWorkspace` succeeds, via `fh.truncate(0)` on the
fd we already hold. fd-based truncate does NOT re-resolve the path
— an attacker swapping the parent symlink after we open can't
redirect the truncation.

#### Fix 3 (wenshao Suggestion): `canonicalizeExistingAncestor`
missing `ELOOP` catch

Circular symlinks in the parent path (`a -> b`, `b -> a`) cause
`fs.realpath` to fail with `ELOOP`. Without catching it, the error
propagates as an unstructured HTTP 500 instead of the typed
`WorkspaceInitSymlinkError` (HTTP 400) the route handler expects
from the workspace-init race-detection family.

Fix: add `'ELOOP'` to the caught error codes alongside `'ENOENT'`
and `'ENOTDIR'`. Walking up the parent chain when ELOOP hits at a
sub-component preserves the existing "walk to the deepest extant
ancestor" contract — the deepest realpath-able ancestor still
dictates the canonical prefix.

#### Why no new tests in this commit

- Fix 1 is a single-line removal: any regression that re-adds the
  unlink would be caught by reviewing the diff; existing 174-test
  `httpAcpBridge.test.ts` integration suite confirms the create-path
  still works (file is created + closed correctly; only the
  attacker-cleanup branch changes).
- Fix 2 is a structural move (truncate from open-time to post-verify);
  the existing overwrite-init integration tests confirm the
  end-to-end behavior is unchanged (file ends up empty after init).
  Adding a TOCTOU race regression test requires controlled
  filesystem-race simulation that exceeds reasonable test infra
  scope for this PR.
- Fix 3 is a one-word addition to an error code list; the
  `canonicalizeExistingAncestor` helper is module-private and the
  integration test for circular-symlink → typed 400 would require
  exporting it OR setting up a real circular-symlink workspace.
  Both routes widen scope beyond the security fix itself; the
  high-level behavior is verifiable by the existing route-error-
  mapping test pattern + diff review.

A follow-up PR can add the integration tests once the security fix
itself has shipped; the immediate priority is closing the
arbitrary-file-deletion + arbitrary-file-truncation primitives.

- 62/62 acp-bridge tests pass
- 174/174 cli httpAcpBridge.test.ts pass
- typecheck + eslint clean

#### Refs

- Original review on #4297 (wenshao via qwen-latest agent), post-
  merge, currently unresolvable on #4297 itself because that PR is
  already MERGED.
- Other 2 #4297 review threads (`const.ts` test coverage,
  `runQwenServe.ts` malformed-context observability) target files
  outside F1's scope and will land as separate follow-up PRs.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix: post-merge Codex P2 fold-in — MCP restart disabled-tools normalization + SDK timeout headroom (#4319)

Folds in 2 P2 findings from a Codex review run on `git diff main...HEAD`
of F1 PR #4319. Both are pre-existing in code merged into
`daemon_mode_b_main` before F1 was created (#4282 PR 17), but they're
tiny tactical fixes (~25 LOC + 1 LOC) on the same integration branch
the same reviewer (wenshao) already engages with, so folding into F1
saves an extra follow-up PR cycle.

#### Fix 1: normalize disabled tool names during MCP restart refresh

`packages/cli/src/acp-integration/acpAgent.ts:1563-1566`

The bootstrap path in `cli/src/config/config.ts:1426-1434` applies a
4-step normalization to `tools.disabled`:
  1. typeof string filter
  2. .trim()
  3. drop empty after trim
  4. dedupe via Set

The MCP-restart refresh path only did step 1, then stored the raw
strings. `ToolRegistry` checks disabled tools with EXACT
`Set.has(tool.name)`, so a tool disabled at boot as `' Foo '` (or
`'Foo\n'`) is no longer matched after `restartMcpServer` and gets
silently re-registered. This contradicts the documented "toggle +
restart" workflow that #4282 PR 17 advertised.

Fix: mirror the bootstrap normalization verbatim before
`setDisabledTools`. Adds 6 lines + a 7-line comment pointing at the
bootstrap reference for future maintainers.

#### Fix 2: add headroom to MCP restart SDK timeout

`packages/sdk-typescript/src/daemon/DaemonClient.ts:102`

The SDK's `MCP_RESTART_DEFAULT_TIMEOUT_MS` was EXACTLY 300_000ms, the
same ceiling the daemon's own `MCP_RESTART_TIMEOUT_MS` uses for the
upper bound on a single MCP rediscovery. For restarts that finish
(or fail with a typed `McpServerRestartFailedError` JSON envelope)
near 300s, the client `AbortSignal` could fire BEFORE the daemon had
finished serializing + transmitting the response, yielding a client
`TimeoutError` even though the daemon was still within its own
budget.

Fix: bump to 330_000ms (10% / 30s headroom over the daemon ceiling).
Comment updated to call out the race + the rationale for the
specific headroom value. Callers needing tighter caps still pass
their own `timeoutMs` to `restartMcpServer`.

#### Why folded into F1 vs separate follow-up PRs

These are post-merge findings on `#4282 PR 17` code, not F1-introduced
regressions. Normally we'd track as separate follow-up issues (mirror
of the #4325 / `channelInfo` decline). But:

- Both fixes are TINY (~25 LOC + ~2 LOC including comment); the bridge
  security fold-in commit `7bd66c6e8` set the precedent of folding in
  small same-branch issues when the cost-benefit favors closing them
  immediately.
- Same reviewer (wenshao via qwen-latest agent) — won't be confused
  by the scope expansion; in fact the original PR 17 commenter is
  also the one who'd review the follow-up issue's fix.
- Both fixes target `daemon_mode_b_main`-only paths (MCP restart route
  added by PR 17 lives on the integration branch).
- Saves opening 2 trivial follow-up issues that would just sit until
  someone picks them up.

#### Verification

- sdk-typescript: 424/424 tests pass (no test hardcoded the old
  300_000 default — only the constant declaration itself referenced it)
- cli acp-integration: 282/282 tests pass (no test exercised the
  exact whitespace-bearing disabled-tools scenario, so no test
  changes were strictly required; a regression test would belong in
  a separate test-coverage PR alongside the const.ts test gap from
  the #4297 unresolved-comment thread)
- typecheck clean across cli + sdk-typescript

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): wenshao review round 4 — 3 Suggestion fold-ins (#4319)

1. **bridge.ts:2270 stale line refs in `publishWorkspaceEvent` JSDoc**
   — comment said `permission_resolved at line 1717` (actual: line 682)
   and `broadcastWorkspaceEvent closure at ~line 2127` (actual: line
   1281). Line numbers drifted across the lift commits. Replaced both
   with function-name refs (`in resolvePending`, `declared above in
   this factory body`) that survive future edits.

2. **`ws.ts:613` opaque references in bridgeFileSystem.ts:20 +
   bridgeOptions.ts:267** — no `ws.ts` file exists in the repo; the
   ref came from an internal review thread on PR 18 that future
   readers can't locate. Replaced with a self-contained description
   ("post-PR-18 follow-up thread about BridgeClient's inline fs proxy
   bypassing WorkspaceFileSystem (origina…

… approval-mode serialization, catch-up indicator) (#4510)

* fix(serve): post-merge fixes for #4291 review (7 threads) (#4305)

* fix(serve): address qwen-latest review on merged #4291 (7 threads)

Seven post-merge findings from the qwen-latest review on #4291,
all real. Most are tightening fixes for issues introduced by the
earlier rounds of #4291 — the same security / DRY / observability
classes the original review surfaced, applied to surfaces that
weren't covered initially.

#1 (deviceFlow.ts:1179) — late-poll observer closure retained the
entire entry by reference (deviceCode/pkceVerifier BrandedSecrets +
cancelController) for the lifetime of the daemon if `provider.poll()`
never settled. Memory leak + indefinite secret retention. Destructure
the four fields the closure actually needs (deviceFlowId, providerId,
initiatorClientId, audit sink) so the entry is GC-eligible the
moment runPollTick returns.

#2 (server.ts) — `callerIsInitiator` was duplicated verbatim across
three locations: GET handler, toDeviceFlowStartResponseBody,
toDeviceFlowStateBody. The exact bug class #4291 was fixing was
"POST and GET diverged on the same redaction policy" — duplicating
the gate recreated the preconditions for divergence. Extracted to
shared `callerIsDeviceFlowInitiator(view, callerClientId)` helper
with the consolidated threat-model JSDoc. All three sites now call
the helper.

#3 (deviceFlow.ts:1110) — timeout callback constructed two separate
`DeviceFlowPollTimeoutError` instances (one for `signal.reason`, one
for the wrapper rejection). Each capture its own V8 stack trace,
and `signal.reason.stack` would diverge from the caught rejection's
stack — confusing for operators inspecting both. Build the sentinel
ONCE per timer fire and pass the same instance to both sites.

#4 (qwenDeviceFlowProvider.ts:273) — `Error.name` is a freely
assignable string property; a hostile fetch wrapper could set
`e.name = 'X\n[serve] FAKE LINE\x1b[31m'` to inject log lines or
ANSI sequences via the same vector we already closed for `oauthError`.
The non-OAuth catch path interpolated `${err.name}` raw. Apply the
same `sanitizeForStderr()` helper.

#5 (deviceFlow.ts:1551) — on the timeout path, `rawProviderError`
is undefined (deliberately, to skip the misleading
`provider.poll() threw (raw): ...` audit template), but that left
the audit hint field omitted entirely. Operators reading the
durable audit trail saw `errorKind: 'upstream_error'` with no signal
whether it was a hung IdP or a generic provider failure. Use
`result.hint` (which already carries the timeout-specific
`provider.poll() timed out after Nms; check IdP connectivity` text
built in the catch) so the audit matches the SSE event.

#6 (server.ts) — the `QWEN_SERVE_DEBUG` env-var check was inlined
in the GET route handler, duplicating the `isServeDebugMode()`
helper from `./debugMode.js` that workspaceAgents and
workspaceMemory already use. The inline copy also had a dead `?? ''`
fallback (the value is guaranteed truthy at that point per the
preceding check). Use the canonical helper.

#7 (deviceFlow.ts:1217) — late-rejection observer interpolated the
raw `lateErr.message` into the audit hint (truncated to 256 bytes,
but RFC 8628 `device_code` values fit comfortably in 256 bytes).
The provider's catch already uses the `name + length` redaction
pattern to prevent WAF-echoed `device_code`/PKCE leaks; the
registry layer was undoing that hardening because the same failure
settled late. Apply the same `name + length` pattern at the late-
rejection site.

Tests:
- Existing late-rejection test reseeded with a `device-code-secret-*`
  substring inside the long detail; hard-negative-asserts the seeded
  secret is absent from the audit + asserts the new
  `Error (message N bytes; raw suppressed)` shape.
- Existing poll-timeout test now also asserts: hint IS defined on
  the audit (not omitted), hint contains `'timed out after'` /
  `'check IdP connectivity'`, and `signal.reason instanceof
  DeviceFlowPollTimeoutError` (proves the single sentinel is
  shared between abort and reject).
- New `sanitizes control characters in attacker-controlled
  err.name` test in qwenDeviceFlowProvider.test.ts pins the round-4
  #4 fix with a hostile `e.name` containing `\n` + `\x1b[31m...`.

cli serve 702/702 (was 686, +16 — additional tests imported via
the acp-bridge package lift on main); sdk 421/421; typecheck clean
across all 4 workspaces; eslint --max-warnings 0 clean on touched
files.

Refs: #4175, #4255, #4291

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): address deepseek-v4-pro review on #4305 (4 threads)

Round-5 fold-in. Four findings from the deepseek-v4-pro review on
PR #4305 — all real, three are sister fixes for the same security
classes that #4305 already closed at adjacent surfaces.

#1 (deviceFlow.ts) — `pollTimedOut` race correctness. The flag was
set unconditionally inside the timer callback. If the provider
settled the wrapper at 29.9s, `finally` would call
`clearScheduled(pollTimer)` — but if the timer callback was already
queued for execution before the clear landed (a real possibility
in Node's event-loop ordering, even if not always observed in
practice), this branch could still run and incorrectly mark
`pollTimedOut`. Move the flag assignment to the catch block where
the settled cause is unambiguous via `instanceof
DeviceFlowPollTimeoutError`. New test pins the negative: provider
beats the timeout → no spurious `lost_late_poll_after_timeout`
audit even after ticking 2× the ceiling.

#2 (deviceFlow.ts) — late-rejection observer interpolated raw
`lateErr.name` into the audit hint without sanitization. Same
attacker-controlled vector closed at the provider layer for
`err.name` in round-4. Route through `sanitizeForStderr`.

#3 (deviceFlow.ts) — late-success observer interpolated
`latePollResult.kind` directly into the audit template. While the
typed shape is `'pending' | 'slow_down' | 'success' | 'error'`, a
non-conforming provider could return an arbitrary string. Same
log-injection vector. Route through `sanitizeForStderr`.

#4 (qwenDeviceFlowProvider.ts → deviceFlow.ts) —
`sanitizeForStderr` only stripped ASCII C0/C1 + DEL; bypass via
Unicode lookalikes:
  - U+2028/U+2029: LINE/PARAGRAPH SEPARATOR (newline-equivalent in
    most Unicode-aware terminals — most direct log-forging vector)
  - U+200B–U+200F: zero-width chars + LRM/RLM
  - U+202A–U+202E: bidirectional override controls
  - U+FEFF: BOM / ZWNBSP

A malicious IdP returning `slow_down
[serve] FAKE` in
`oauthError` would otherwise still forge log lines.

Architectural change: `sanitizeForStderr` was previously private to
`qwenDeviceFlowProvider.ts`. To address #2/#3, the registry layer
needs to call it too. Lifted into `deviceFlow.ts` (the foundation
module) and re-imported from the provider. Single source of truth;
the regex is now a module-level constant compiled once with explicit
`\uXXXX` escapes (via `String.raw` so the source is greppable, not
literal-Unicode-laden).

Tests:
- `does NOT attach late-poll observer when the provider beats the
  timeout` — N1 race regression
- `sanitizes hostile latePollResult.kind in late-observer audit` — N3
- `sanitizes hostile lateErr.name in late-rejection observer audit` — N2
- `sanitizes Unicode lookalike controls (U+2028 LINE SEPARATOR,
  bidi, ZWNBSP) in oauthError` — N4

cli serve 706/706 (was 702, +4 — all new round-5 tests); sdk
421/421; typecheck clean; eslint --max-warnings 0 clean on touched
files.

Refs: #4175, #4255, #4291, #4305

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): address gpt-5.5 + qwen-latest review on #4305 round-5 (5 threads)

Round-6 fold-in. Five findings split between maintainability,
security hardening, and a real defensive bug.

#1 (qwenDeviceFlowProvider.test.ts) — gpt-5.5: round-5 #4 test
embedded U+2028 / U+200E / U+FEFF as literal characters in source.
Invisible in GitHub diffs / most editors; the negative
`not.toContain('')` looked like an empty-string check. Rewrote
the payload + assertions to use named `\uXXXX`-bound constants.
Also added a companion test exercising U+2066–U+2069 (round-6 #5
below).

#2 (deviceFlow.ts) — qwen-latest: the late-poll observer's
`void tracked.then(...)` was missing a terminal `.catch(() => {})`.
A synchronous throw inside either handler (e.g., a misbehaving
`audit.record`: backpressure, malformed payload, sink out-of-disk)
would reject the derived promise unhandled. On Node 22's default
`--unhandled-rejections=throw`, that crashes the daemon. Added the
terminal `.catch(() => {})` matching the persist-tracker pattern.
New test injects a poison audit sink that throws specifically on
the `lost_late_poll_after_timeout` call; asserts `flushAsync()`
resolves cleanly.

#3 (deviceFlow.ts) — qwen-latest: the `case 'error'` audit-record
hint interpolated `rawProviderError` (raw `err.message`) without
`sanitizeForStderr`. Per ES2019+ `JSON.stringify` no longer escapes
U+2028/U+2029 — those would still forge log lines downstream
through file/stdout audit sinks. Apply the same sanitizer used on
every other provider-controlled audit path. New test pins a hostile
provider message containing U+2028 + ANSI escape and asserts
neither survives.

#4 (deviceFlow.ts) — qwen-latest: the round-5 #1 comment claimed
"`DeviceFlowPollTimeoutError` isn't exported as a public DeviceFlow
contract", but it IS `export class` (the test file constructs it
directly for fixtures). With `pollTimedOut = true` keyed solely on
`instanceof`, a future provider that imports + throws the class
would spoof the registry's "I caused the timeout" signal —
attaching a phantom late-poll observer.

Fix: introduce a runtime brand `_isRegistryTimeout: boolean` on the
class (default `false`) plus an internal-only
`makeRegistryPollTimeoutError(ms)` helper that sets the brand to
`true`. The brand is set ONLY at the registry's race-timer
construction site. Both gates updated:
  - `if (err instanceof X && err._isRegistryTimeout === true)` in
    the catch (for `pollTimedOut`)
  - `if (lateErr instanceof X && lateErr._isRegistryTimeout === true)`
    in the late-rejection self-filter

A provider-thrown brand-false instance now flows through the
generic provider-throw audit path — correctly auditing the misuse
rather than silently swallowing it. Repurposed the original "no
double-audit when registry's own DeviceFlowPollTimeoutError is
late-rejected" test (which was actually exercising the brand-false
path) into the inverted assertion: brand-false provider throw IS
audited as a real failure. Removed the orphaned old assertion; the
brand-true happy path is implicitly covered by the hanging-provider
test (which exercises the registry-built timeout end-to-end).

#5 (deviceFlow.ts) — qwen-latest: `sanitizeForStderr` regex covered
U+202A–U+202E (bidi embedding/override) but missed U+2066–U+2069
(LRI/RLI/FSI/PDI). These are the primary CVE-2021-42574
("Trojan Source") attack vectors — a hostile IdP swapping U+2066
for U+202D achieves the same visual reordering and would have
bypassed the round-5 filter entirely. Extended the regex range and
JSDoc; new test exercises U+2066/U+2068/U+2069 in `oauthError` and
asserts none survive while substantive ASCII parts remain.

cli serve 713/713 (was 710, +3 round-6 tests + the round-5 #4
rewrite + the round-6 #5 companion); typecheck clean across all 4
workspaces; eslint --max-warnings 0 clean on touched files.

Refs: #4175, #4255, #4291, #4305

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): replace literal U+2028 with explicit 
 escape in round-6 #3 test

PR #4312 review (Copilot): the round-6 #3 test (sanitizes
rawProviderError) regressed back to embedding a literal U+2028
character in source via `const U_2028 = ' '`. That's the same
maintainability anti-pattern round-6 #1 was fixing in the sister
test. Internal-consistency fix: switch to the explicit `
`
escape so the constant is greppable and reviewable in GitHub diffs.

Refs: #4291, #4305, #4312

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(serve): post-merge P2 corrections from Codex review on #4282 (#4297)

* fix(serve): post-merge P2 corrections from Codex review on #4282

Follow-up to PR #4282 (Wave 4 PR 17) addressing four P2 issues
flagged by Codex's `/review` after the squash-merge to main:

P2-1 — Read the workspace context filename for init
  `qwen serve` parent never goes through `loadCliConfig`, so the
  process-global `getCurrentGeminiMdFilename()` stays on the default
  `QWEN.md` even when the workspace configures
  `context.fileName: 'AGENTS.md'`. `runQwenServe` now snapshots the
  workspace's merged setting at boot and forwards via
  `BridgeOptions.contextFilename`, so init writes the same file the
  ACP child reads.

P2-2 — Restart MCP servers with a fresh disabledTools snapshot
  `Config.disabledTools` was frozen at construction time;
  `setWorkspaceToolEnabled` only updated settings.json. The
  documented "toggle + restart" workflow re-registered just-disabled
  tools because rediscovery still saw the bootstrap snapshot. Added
  `Config.setDisabledTools()` plus a re-read at the ACP restart
  handler so `discoverMcpToolsForServer` honors the latest set.

P2-3 — Match the SDK timeout to the daemon's restart budget
  Bridge waits up to 300s for stdio MCP discovery; SDK helper used
  the client-wide 30s default and aborted valid slow restarts.
  Added a per-call `timeoutMs` plumbed through `fetchWithTimeout`,
  defaulting `restartMcpServer` to 5 minutes.

P2-4 — Reject symlinked parent directories before init writes
  `lstat(target)` only checked the final component; a symlinked
  parent (e.g. `docs -> /tmp` with `context.fileName:
  'docs/QWEN.md'`) would let `writeFile` follow the link and create
  / truncate outside `boundWorkspace`. Added
  `canonicalizeExistingAncestor` (walks up through ENOENT to the
  deepest extant ancestor, then `realpath`s) and verifies the
  canonical parent stays within the canonical workspace.

5 new tests (4 bridge / 2 SDK):
- contextFilename snapshot honored
- parent-symlink escape rejected
- nested real subdir accepted
- restartMcpServer survives 1.2s response with 1s default timeout
- restartMcpServer honors a 50ms caller override

Typecheck clean across cli / sdk-typescript / core.
1604/1604 unit tests pass.

* fix(serve): fold-in 1 — address 16:32:44-round review on #4282

Follow-up addressing the 8 unresolved review threads opened on PR
shipping in this same #4297; addresses correctness gaps + missing
test coverage that would otherwise let regressions ride into main.

Behavior fix:
- broadcastWorkspaceEvent gains a `skipSessionId` parameter; when
  `setSessionApprovalMode` runs with `persist:true`, the broadcast
  skips the requesting session so it doesn't receive the same
  `approval_mode_changed` event twice (once via session-scoped
  publish + once via broadcast). The SDK reducer's
  `approvalModeChangedCount` now increments by 1, not 2, on the
  requesting client (peers still see 1 via the broadcast).
  Addresses #3260501134.

Observability + posture:
- broadcastWorkspaceEvent now mirrors PR 16's publishWorkspaceEvent
  member: per-entry success/failure accounting + an "ALL buses
  dropped" stderr elevation. The previous local helper silently
  swallowed every publish failure. Addresses #3260501126.
- WorkspaceInitPathEscapeError + WorkspaceInitSymlinkError typed
  classes for the two boundary guards in initWorkspace, mapped to
  HTTP 400 by sendBridgeError. Previous generic `Error` fell
  through to the 500 handler, telling operators "daemon broken"
  when the actual fix was workspace-config correction. Addresses
  #3260501161.

Public surface symmetry:
- Re-export McpServerNotFoundError, McpServerRestartFailedError,
  WorkspaceInitPathEscapeError, WorkspaceInitSymlinkError from the
  serve barrel. External embeds matching these via `instanceof`
  no longer need deep imports. Addresses #3260501163.

Test coverage:
- restartMcpServer bridge tests (5): success + event broadcast,
  soft-skip + refused event, McpServerNotFoundError translation,
  McpServerRestartFailedError translation, originator clientId
  stamping. Addresses #3260501141.
- sendBridgeError mapping tests (4): McpServerNotFoundError → 404,
  McpServerRestartFailedError → 502, WorkspaceInitPathEscapeError
  → 400, WorkspaceInitSymlinkError → 400. Addresses #3260501148.
- initWorkspace boundary guard tests (2 added): symlink-at-target
  rejected, contextFilename '../outside.md' rejected. Addresses
  #3260501157.
- TrustGateError tests assert the typed class via `.toThrow(TrustGateError)`,
  not just message text. Addresses #3260501165.

Also updates the existing fold-in 4 S2 broadcast test to reflect
the new no-duplicate semantics on the requesting session.

Typecheck clean across cli / sdk-typescript / core.
1615/1615 unit tests pass.

* fix(serve): fold-in 2 — copilot + wenshao review on #4297

Round-2 reviewer adoption on the same PR:

Critical fixes:
- `restartMcpServer` JSDoc documents `timeoutMs: 0` as "disable the
  timeout entirely", but the `> 0` guard in `fetchWithTimeout`
  rejected `0` and silently fell back to the 30s client default.
  Loosened the guard to `>= 0` so `0` flows through to the
  no-timeout branch via the existing truthiness check; NaN /
  negative inputs still coerce to the client default. Addresses
  duplicate reports from copilot (#3260577538) and wenshao
  (#3260661833).
- TS2322 in the slow-fetch test stub: `resolveResponse` was typed
  against `import('undici-types').Response` but assigned a
  `(v: Response) => void`. Re-typed against the global `Response`
  throughout. Caught only by tsc runs that include the test
  files. Addresses #3260663072.

Test fidelity:
- Slow-fetch stub now observes `init.signal` and rejects on abort,
  so a regression that drops the per-call `timeoutMs` override
  will reliably fail the test instead of resolving after the
  timer fired (false-negative coverage). Addresses #3260577600.
- New test pinning the `timeoutMs: 0` semantics: 1ms client
  default + a stub that resolves after 50ms. Without the `>= 0`
  fix, the call would abort at 1ms; with it, the explicit
  `0` disables the timer and the call completes.

Bug fixes:
- `runQwenServe.contextFilenameForInit` previously called
  `String(arr[0])` on the array branch, producing a literal
  `"[object Object]"` filename for hand-edited bad data. Now
  validates each element with `typeof === 'string'` and falls
  back to `undefined` (so the bridge uses its
  `getCurrentGeminiMdFilename()` default) when no string is
  found. Addresses #3260577641.

Documentation drift:
- `Config.getDisabledTools()` JSDoc rewritten to describe the
  mutable-via-`setDisabledTools()` semantics introduced by P2-2,
  and the "registration-time only / no retroactive unregister"
  contract that pairs with it. Old comment claimed the set was
  frozen at construction. Addresses #3260577677.

Observability:
- `acpAgent` MCP-restart `loadSettings` failure now surfaces a
  stderr line naming the server + the underlying error, instead
  of silently swallowing it. The documented "toggle + restart"
  workflow used to break with zero diagnostic when settings.json
  was corrupted or unreadable. Addresses #3260663303.

Code organization:
- Moved `canonicalizeExistingAncestor` after `describeStatKind` so
  the latter's JSDoc is no longer orphaned (TypeScript only
  associates the last `/** ... */` block before a declaration).
  Addresses #3260668618.

Typecheck clean across cli / sdk-typescript / core.
1616/1616 unit tests pass.

* fix(serve): fold-in 3 — read merged scope on MCP restart refresh

Critical bug from wenshao review (#3260725526) on PR #4297:
the P2-2 acpAgent re-read narrowed `Config.disabledTools` to
`SettingScope.Workspace` alone, dropping User / System scope
entries. The bootstrap Config received `merged.tools?.disabled`
(union of all scopes), so user-level / system-level disables
worked at boot — but the first `mcp restart` would replace the
in-memory set with the workspace scope alone, silently re-enabling
any tool that was disabled at a higher scope but absent from the
workspace file.

The asymmetry vs. the persist-write path is deliberate and
documented:
- Reads (here): merged — match the bootstrap Config snapshot,
  preserve user/system policy.
- Writes (`runQwenServe.persistDisabledTools`): workspace scope —
  don't bake higher-scope entries into the workspace file
  (per-#4282 fold-in 1 H2 fix).

Two paths look alike but answer different questions.

Typecheck clean across cli / sdk-typescript / core.
1616/1616 unit tests pass.

* fix(test): fold-in 4 — wire timeoutMs:0 stub to init.signal

Critical follow-up from wenshao (#3260810242) on PR #4297:
the new `timeoutMs: 0` regression test (added in fold-in 2)
inherited the same flaw it was meant to prevent — the slow-fetch
stub didn't observe `init.signal`, so a regression that ignored
the `0` override would fire the AbortController at the 1ms client
default but the stub would keep the promise pending. The 50ms
`resolveResponse` would win, the test would still pass, and the
documented "0 disables timeout" contract would be unprotected.

Mirrored the listener pattern already used by the two sibling
tests in fold-in 2 — `init.signal.addEventListener('abort', () =>
reject(...))`. Now a regression that re-rejects `0` triggers the
abort, the stub rejects, the test fails.

8/8 restartMcpServer SDK tests pass; SDK typecheck clean.

* fix(serve): fold-in 5 — TOCTOU + setDisabledTools coverage

Two new critical reviews from wenshao on PR #4297:

C1 — TOCTOU between lstat and writeFile (#3260836305):
The `lstat(target)` symlink check and the subsequent `writeFile`
were two separate syscalls, leaving a race window where a local
attacker with workspace write access could substitute a symlink
between them. With `force: true`, `writeFile` would follow the
link and truncate an external target.

The `action === 'created'` path now uses `fs.open(target, 'wx')`
(O_WRONLY|O_CREAT|O_EXCL), which atomically refuses any
pre-existing inode (regular file, dir, OR symlink) at the target
path. EEXIST after the absence check most plausibly means a
race-created symlink, so we throw `WorkspaceInitSymlinkError(kind:
'target')` — same typed class the route maps to 400.

The `force: true` overwrite path retains the existing TOCTOU as a
documented limitation; closing it requires `O_NOFOLLOW`-aware open
which the post-PR18 `WorkspaceFileSystem` migration will provide.

C2 — P2-2 zero test coverage (#3260836302):
The `setDisabledTools` runtime sync was the only Wave-4 P2 fix
without a dedicated test. Added 5 Config-level tests:
- Initializes from `disabledTools` ConfigParameters
- Defaults to empty set when omitted
- `setDisabledTools` replaces the live snapshot
- Defensive copy: caller-set mutations don't leak into the live snapshot
- Accepts an empty set (clears live snapshot)

Plus a TOCTOU regression test in httpAcpBridge.test.ts that
spies fs.lstat / fs.readFile to simulate the race window:
pre-creates a symlink, makes lstat lie about it, asserts the
'wx' open catches the racing inode and throws the typed
`WorkspaceInitSymlinkError(kind: 'target')`.

1622/1622 unit tests pass; typecheck clean across cli /
sdk-typescript / core.

* fix(serve): fold-in 6 — count actual skips in broadcast alarm

DeepSeek review on #4297 (#3261079572):
`broadcastWorkspaceEvent` unconditionally subtracted 1 from the
`eligible` recipient count whenever `skipSessionId` was set, even
when the id matched zero live sessions (caller mistake, stale id,
or the matching session was just torn down between resolution and
broadcast). In a single-session workspace that's the difference
between `eligible = 0` (alarm suppressed) and `eligible = 1`
(alarm fires when the publish failed) — silently losing the
all-dropped breadcrumb the telemetry was meant to surface.

Today's call sites pass real session ids so the bug doesn't
manifest in practice, but the defensive shape is small: track
`skippedCount` inside the loop and subtract that, so the alarm
condition is self-consistent regardless of how the caller mis-uses
the param.

162/162 bridge tests pass; CLI typecheck clean.

* fix(serve): fold-in 7 — close overwrite TOCTOU, harden boot + diagnostics

Round-7 review on PR #4297. Three critical fixes + one suggestion
test, plus a regression test for the overwrite TOCTOU close.

C1 — force:true overwrite TOCTOU (#3262615446):
The fold-in 5 fix only closed the `'created'` action via 'wx';
the `'overwrote'` branch still used plain `fs.writeFile`, so a
local writer could swap the verified regular file to a symlink
between the lstat/readFile checks and the write and have the
forced overwrite truncate an external target. Switched to
`fs.open(target, O_WRONLY | O_TRUNC | O_NOFOLLOW)` — `O_NOFOLLOW`
makes open() fail with ELOOP on a symlink at the final component
even under race. ELOOP / ENOENT (race-deleted) translate to
`WorkspaceInitSymlinkError(kind: 'target')` so the route still
maps to a structured 400 instead of a generic 500.

C2 — settings.json corrupt blocks daemon boot (#3262625091):
`loadSettings(boundWorkspace)` at boot had no try/catch — a
corrupted, malformed, or temporarily unreadable settings file
threw synchronously and prevented daemon startup. Pre-PR this
never happened because settings were read lazily inside request
handlers. Wrapped in try/catch with stderr fallback so the daemon
keeps booting (with the bridge's default context filename) when
the file is broken.

C3 — malformed `tools.disabled` clears policy silently (#3262625101):
When `merged.tools?.disabled` is present but not an array
(boolean / string / object from a hand-edited settings.json), the
ternary `Array.isArray(...) ? ... : []` substituted an empty list
without firing the surrounding catch block. After an MCP restart
every disabled tool would silently re-register. Added an explicit
`!Array.isArray && !== undefined` check that stderr-logs the
malformed type before clearing — operators see the
misconfiguration instead of a stealth re-enable.

S1 — contextFilename extraction tested (#3262690842):
Lifted the inline `firstStringInArray` + branching into an
exported `extractContextFilename(value: unknown)` helper and
added `runQwenServe.test.ts` with 5 tests covering the four
branches the suggestion called out: non-empty string, array with
strings, array with no strings, non-string non-array.

Plus a TOCTOU regression test for the overwrite path that
verifies `O_NOFOLLOW` returns `WorkspaceInitSymlinkError(kind:
'target')` when the file is race-substituted with a symlink
behind the lstat/readFile mocks.

S2 (acpAgent restart-handler integration test #3262690845) is
deferred — Config-level coverage of `setDisabledTools` already
locks the load-bearing surface (5 tests in fold-in 5), and
adding a full acpAgent integration test requires heavy ext-method
plumbing. The new C3 stderr diagnostic plus existing tests give
us the regression signal we need without that scaffolding.

1627/1627 unit tests pass; typecheck clean across cli /
sdk-typescript / core / acp-bridge.

* fix(serve): fold-in 8 — split ELOOP / ENOENT diagnostic in overwrite path

qwen-latest review on PR #4297 (#3262861754):
The fold-in 7 ELOOP/ENOENT branch shared one error message that
said "swapped to a symlink." That's accurate for ELOOP (genuine
O_NOFOLLOW rejection — likely an attack race) but misleading for
ENOENT in the overwrite path: there `readFile` just succeeded
proving the file existed, so ENOENT means the file was DELETED
between the content check and the open — a benign race with a
concurrent writer (git checkout, editor save, lockfile rename),
NOT a symlink swap. An operator seeing the symlink language for
a benign delete would `ls -la`, see no symlink, and waste time
hunting an attack that didn't happen.

Split into two messages:
- ELOOP: "swapped to a symlink between the content check and the
  overwrite — refusing to follow it"
- ENOENT: "deleted between the content check and the overwrite
  (likely a concurrent writer) — refusing to recreate blindly"

Both still surface as `WorkspaceInitSymlinkError(kind: 'target')`
so the route maps to a structured 400; the class doubles as the
workspace-init race-condition bucket with kind='target' meaning
"target inode misbehaved at write time" generally.

Updated the existing fold-in 7 TOCTOU test to assert the ELOOP
message specifically, and added a new ENOENT race-delete test
that mocks lstat/readFile to land on the overwrote action against
a non-existent path — verifies the message says "deleted" and
NOT "swapped to a symlink."

170/170 bridge tests pass; CLI typecheck clean.

* fix(serve): fold-in 9 — route MCP restart through registry cleanup wrapper

gpt-5.5 critical review on PR #4297 (#3263088414):

The fold-in 5 P2-2 fix refreshed `Config.disabledTools` from merged
settings, but then called `manager.discoverMcpToolsForServer()`
directly — bypassing the `ToolRegistry.discoverToolsForServer`
wrapper that PURGES the server's existing `DiscoveredMCPTool`
entries (and `revealedDeferred` markers) plus its prompts before
rediscovery. Without the cleanup, `registerTool` only consulted
the refreshed `disabledTools` set for NEWLY-discovered tools —
entries already in the registry from the prior MCP boot kept
serving requests. Net effect: toggle-disable-then-restart
silently left the disabled tool live, breaking the documented
"toggle + restart" workflow that P2-2 was meant to fix.

Routed through `toolRegistry.discoverToolsForServer(serverName)`
which:
1. Removes existing `DiscoveredMCPTool` entries for this server
2. Drops their `revealedDeferred` reveal state
3. Removes the server's prompts via `removePromptsByServer`
4. THEN delegates to `manager.discoverMcpToolsForServer` for the
   actual reconnect + rediscover

The pre-discovery budget / in-flight checks still go through the
`manager` reference (which is the same object the registry
wrapper would forward to) — so soft-skip semantics for
`budget_would_exceed`, `in_flight`, `disabled` are preserved.

CLI typecheck clean; 403/403 server + bridge tests pass.

* fix(serve): fold-in 10 — qwen-latest 05:45-round review on #4297

5 review threads from qwen-latest's late round on PR #4297 (now closed
in favor of #4313 against `daemon_mode_b_main`). 1 critical + 4
suggestions, all adopted.

C1 — extractContextFilename / getCurrentGeminiMdFilename divergence
(#3263954685): with `context.fileName: ['  ', 'AGENTS.md']`, the
daemon parent's `extractContextFilename` (which skips empty entries)
wrote `AGENTS.md`, but the ACP child's `getCurrentGeminiMdFilename`
(which returned `arr[0]` unconditionally) read `''`. The init'd file
was orphaned. Aligned `getCurrentGeminiMdFilename` to skip empty
entries with the same semantics, falling back to
`DEFAULT_CONTEXT_FILENAME` when all entries are empty.

S2 — WorkspaceInitSymlinkError reused for non-symlink races
(#3263954690): the EEXIST race-create and ENOENT race-delete cases
were surfacing as `code: 'workspace_init_symlink'`, misleading
operators into hunting symlink attacks for benign concurrent-
modification windows. Split into a sibling `WorkspaceInitRaceError`
class (`kind: 'eexist' | 'enoent'`, HTTP code
`workspace_init_race`). The genuine symlink class stays for ELOOP,
lstat-detected target symlinks, and parent-realpath escapes.

S3 — fsConstants.O_NOFOLLOW defensive `?? 0` (#3263954697): matches
the existing codebase convention in
`core/src/utils/{sessionStorageUtils,gitDiff}.ts` and
`cli/src/ui/utils/customBanner.ts`. Functionally a no-op (JS
bitwise coerces undefined to 0) but consistent.

S5 — Parent-directory TOCTOU still open (#3263954707): O_NOFOLLOW
only protects the final path component; a local writer could swap
a real parent dir for a symlink between
`canonicalizeExistingAncestor` and `fs.open`. Added
`verifyParentWithinWorkspace` post-open helper that re-realpaths
`path.dirname(target)` and refuses with
`WorkspaceInitSymlinkError(kind: 'parent')` if the parent moved.
On the create path (where we just opened with `'wx'`), the failure
also unlinks the file we just made best-effort. Residual race
window narrowed from "between pre-check and open" to "between
post-open realpath and writeFile" — sub-millisecond, documented as
accepted Stage-1 trust posture.

S4 — broadcastWorkspaceEvent vs publishWorkspaceEvent stale comment
(#3263954688): the "now removed" comment was inaccurate (5 call
sites still use the closure). Replaced with an accurate
description of why both coexist (factory closure can't `this`-call
proxy member; closure also takes `skipSessionId` for persisted
approval-mode mirror) and a TODO marker for future helper extraction.

Two existing tests updated to assert the new `WorkspaceInitRaceError`
class for EEXIST / ENOENT scenarios (the symlink-class assertions
are preserved for ELOOP / lstat / parent cases).

1759/1759 unit tests pass; typecheck clean across all 4 packages.

* feat(acp-bridge): F1 — acp-bridge package self-sufficiency (#4175 mechanical lift + BridgeFileSystem seam) (#4319)

* refactor(acp-bridge): lift defaultSpawnChannelFactory to acp-bridge/spawnChannel (#4175 F1 step 1)

First mechanical lift of #4175 F1 (acp-bridge package self-sufficiency).
Moves the production spawn factory + its `killChild` helper +
`SCRUBBED_CHILD_ENV_KEYS` denylist + `KILL_HARD_DEADLINE_MS` constant
from `cli/src/serve/httpAcpBridge.ts` (~283 lines) to
`@qwen-code/acp-bridge/spawnChannel`. This unblocks
`channels/base/AcpBridge.ts` and `vscode-ide-companion`'s
acpConnection from each reimplementing the child lifecycle — they can
now consume the same primitive.

Backward compatible: `cli/src/serve/httpAcpBridge.ts` imports the
lifted factory and re-exports it, so existing references in
`cli/src/serve/index.ts:90` and the factory's own internal usage
(`opts.channelFactory ?? defaultSpawnChannelFactory`) keep resolving.
Bridge tests that mock `defaultSpawnChannelFactory` via
`BridgeOptions.channelFactory` are unaffected.

Side cleanups: drops `spawn` / `ChildProcess` / `Readable` / `Writable`
/ `ndJsonStream` / `MissingCliEntryError` imports from
httpAcpBridge.ts (all only used by the lifted spawn factory).

- 44/44 acp-bridge tests pass
- 174/174 cli httpAcpBridge tests pass
- typecheck clean across acp-bridge + cli

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* refactor(acp-bridge): lift BridgeClient + permission types to acp-bridge/bridgeClient (#4175 F1 step 2)

Second mechanical lift of #4175 F1 (acp-bridge package self-sufficiency).
Moves `BridgeClient` class (~700 LOC) + `PendingPermission` interface +
`PermissionResolutionRecord` interface + `MAX_RESOLVED_PERMISSION_RECORDS`
constant + early-event capacity constants + `describeStatKind` and
`sliceLineRange` helpers from `cli/src/serve/httpAcpBridge.ts` to
`@qwen-code/acp-bridge/bridgeClient`.

Design choice for SessionEntry boundary: introduce a minimal
`BridgeClientSessionEntry` interface in bridgeClient.ts with only the
four fields BridgeClient actually reads from the factory's richer
`SessionEntry` (`sessionId`, `events`, `pendingPermissionIds`,
`activePromptOriginatorClientId`). The factory's `SessionEntry`
structurally satisfies it — TypeScript's structural typing enforces
the match at the `resolveEntry` callback signature, so no explicit
conversion is required and the bridge package stays free of daemon-host
session-bookkeeping types.

Cross-package writeStderrLine handling: inline the 3-line helper in
bridgeClient.ts (mirrors the spawnChannel.ts pattern from F1 step 1)
so acp-bridge has no reverse dependency on `cli/src/utils/stdioHelpers`.

httpAcpBridge.ts shrinks from 4406 LOC to 3647 LOC (-759 lines).
Removed ACP SDK imports that only BridgeClient consumed: `Client`,
`RequestPermissionRequest`, `WriteTextFileRequest`,
`WriteTextFileResponse`, `ReadTextFileRequest`, `ReadTextFileResponse`,
`SessionNotification`. Kept the ones the factory still uses
(`CancelNotification`, `PromptRequest`, `RequestPermissionResponse`,
`SetSessionModelRequest`, `SetSessionModelResponse`).

Backward compatible: httpAcpBridge.ts re-exports `BridgeClient`,
`BridgeClientSessionEntry`, `PendingPermission`,
`PermissionResolutionRecord`, and `MAX_RESOLVED_PERMISSION_RECORDS` so
the `ChannelInfo.client: BridgeClient` field declaration below + any
embedder reaching into these types keep resolving.

- 44/44 acp-bridge tests pass
- 174/174 cli httpAcpBridge tests pass
- 229/229 cli server tests pass
- typecheck clean across acp-bridge + cli

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* refactor(acp-bridge): lift createHttpAcpBridge factory to acp-bridge/bridge (#4175 F1 step 3)

Third + final mechanical lift of #4175 F1 (acp-bridge package
self-sufficiency). Moves the `createHttpAcpBridge` factory closure
(~3000 LOC) + `ChannelInfo` + `SessionEntry` interfaces + factory-only
helpers (`canonicalizeExistingAncestor`, `verifyParentWithinWorkspace`,
`withTimeout`, `isServeDebugLoggingEnabled`, `writeServeDebugLine`,
`hasControlCharacter`) + factory constants (`DEFAULT_INIT_TIMEOUT_MS`,
`MCP_RESTART_TIMEOUT_MS`, `DEFAULT_MAX_SESSIONS`, `MAX_EVENT_RING_SIZE`,
`DEFAULT_PERMISSION_TIMEOUT_MS`, `DEFAULT_MAX_PENDING_PER_SESSION`,
`MAX_DISPLAY_NAME_LENGTH`) from `cli/src/serve/httpAcpBridge.ts` to
`@qwen-code/acp-bridge/bridge`.

`cli/src/serve/httpAcpBridge.ts` shrinks from 3647 LOC to 97 LOC — a
pure re-export shim that preserves every existing relative import
path (`./httpAcpBridge.js`) so `server.ts`, `runQwenServe.ts`,
`workspaceAgents.ts`, `workspaceMemory.ts`, `index.ts`, plus the bridge
test suite, keep resolving without any call-site changes.

The new `bridge.ts` reuses what was already in acp-bridge (errors,
types, options, status helpers, channel types, event bus, workspace
paths) via local relative imports — no reverse dependency on `cli`.
`writeStderrLine` is inlined at the top of `bridge.ts` (same pattern as
`spawnChannel.ts` + `bridgeClient.ts` from F1 steps 1-2) so the
package self-contained promise holds.

Cumulative F1 impact across the 3 mechanical lift steps:
- httpAcpBridge.ts: 4682 LOC → 97 LOC (-4585 lines; the original file
  was 98% bridge core, 2% backward-compat re-exports)
- 3 new files in acp-bridge: spawnChannel.ts (~270 LOC), bridgeClient.ts
  (~745 LOC), bridge.ts (~3515 LOC)
- All daemon-host concerns (env snapshot, daemon preflight cells)
  remain in `cli/src/serve/daemonStatusProvider.ts` and reach the
  bridge through the `BridgeOptions.statusProvider` seam frozen by
  PR 22b/2.

- 735/735 cli serve tests pass across 17 files
- 174/174 cli httpAcpBridge tests pass
- 44/44 acp-bridge tests pass
- typecheck clean across acp-bridge + cli

`packages/cli/src/serve/httpAcpBridge.test.ts` (~6600 LOC) is
intentionally NOT moved in this commit — it currently imports
`createHttpAcpBridge` / `defaultSpawnChannelFactory` / `BridgeClient`
via the cli shim and keeps passing without changes. Moving it to
`acp-bridge/src/bridge.test.ts` is a follow-up worth tracking
separately so the production-code lift can land + be reviewed cleanly.

The `BridgeFileSystem` injection seam (originally bundled into F1 as
the 22b' scope) is also deferred to a follow-up so the mechanical lift
stays mechanical — design + implementation of the fs injection is its
own discussion.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* feat(acp-bridge): add BridgeFileSystem injection seam (#4175 F1 step 5, 22b' scope)

Adds the `BridgeFileSystem` injection seam originally scoped as #4175
22b'. When a `BridgeFileSystem` is wired through
`BridgeOptions.fileSystem`, `BridgeClient.readTextFile` and
`BridgeClient.writeTextFile` delegate to it instead of running their
inline `fs.realpath` / `fs.writeFile` / `fs.readFile` proxy.

This unblocks production `qwen serve` plumbing PR 18's
`WorkspaceFileSystem` (TOCTOU guards, symlink-substitution checks,
trust gate, `.gitignore`, audit hooks) into the ACP fs methods —
closing the `ws.ts:613` follow-up thread that has been tracked since
PR 18 landed. The serve-side adapter that wraps `WorkspaceFileSystem`
+ the `runQwenServe` wiring are intentionally split into the
immediate-follow-up so this PR stays focused on the seam design.

Backward compatible: `fileSystem` is optional on `BridgeOptions`.
Tests, Mode A in-process consumers, channels (`packages/channels/base/
AcpBridge.ts`), and the VSCode IDE companion all keep working
unchanged — they omit the field and `BridgeClient` falls through to
the inline proxy that has been the Stage 1 default since #3889.

API:
- `BridgeFileSystem.readText(params: ReadTextFileRequest):
  Promise<ReadTextFileResponse>`
- `BridgeFileSystem.writeText(params: WriteTextFileRequest):
  Promise<WriteTextFileResponse>`

The interface mirrors ACP SDK request/response types directly so the
adapter does the minimum amount of translation (`{ path, content }`
↔ `WorkspaceFileSystem`'s `ResolvedPath` brand types + options bag).

- 735/735 cli serve tests pass (inline fallback path preserved)
- 44/44 acp-bridge tests pass
- typecheck + eslint clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): catch README + stale source comments up to F1 lift

Self-review fold-in: post-F1 the package README still said "PR 22a"
and listed `BridgeClient` / `createHttpAcpBridge` /
`defaultSpawnChannelFactory` under "What's not here yet" — both
contradicted by this PR. Updated:

- README lift-history table now shows PR 22a / 22b/1 / 22b/2 as
  merged and F1 (this PR) as the slice that closes the bridge core
  + adds `BridgeFileSystem`. F3 PR 24 row aligned to the
  feature-cohesive plan.
- "What's here today" now documents `spawnChannel`, `bridgeClient`,
  `bridge`, `bridgeFileSystem` modules.
- "What's not here yet" section removed (its 2 bullets are both
  resolved by F1).
- Subpath import list updated to enumerate all 14 subpaths.
- Backward-compat section updated to call out the 97-line shim and
  the 6 consuming files that still import via `./httpAcpBridge.js`.

Source-comment line-number drift:
- `channel.ts:12` no longer claims `defaultSpawnChannelFactory` is
  "still in cli/src/serve/httpAcpBridge.ts" — points to the lifted
  location.
- `permission.ts:33` + `permission.ts:45` no longer reference
  `httpAcpBridge.ts:1096-1106` / `httpAcpBridge.ts:1003` (file is
  now 97 lines after F1). Updated to point at the structurally-
  equivalent locations inside the lifted `bridgeClient.ts`.
- `permission.ts:7` no longer says first-responder still lives in
  `cli/src/serve/httpAcpBridge.ts` — points at the bridgeClient.ts
  location.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): adopt 3 Copilot review comments on F1 doc accuracy

Folds in 3 of 4 Copilot inline comments from #4319 review:

1. `bridgeClient.ts` writeTextFile preserveMode comment said "fall
   through to umask defaults" for new files, but the code passes
   `mode: preserveMode?.mode ?? 0o600` to `fs.writeFile`. Updated the
   "BkwQW" comment + the inner catch-block comment to clarify that
   new files actually get the `0o600` default applied at writeFile
   time (NOT umask defaults — the explicit `mode` arg bypasses umask
   for atomicity per the `Blehd` comment block).

2. `bridgeFileSystem.ts` JSDoc referenced
   `cli/src/serve/bridgeFileSystemAdapter.ts` as if the file exists,
   but it's deferred to the immediate F1 follow-up PR. Reworded as
   "the immediate follow-up PR will land a serve-side adapter" so
   reviewers don't grep for a non-existent file.

3. `bridgeOptions.ts` `fileSystem` field JSDoc had the same wording
   issue ("Production `qwen serve` wires this to..."). Same fix — now
   says "The immediate F1 follow-up will land a serve-side adapter"
   so the deferred state is obvious.

Declined from this review round:

- Copilot inline #1 (`spawnChannel.ts:155` stderr forwarder drops
  empty lines): pre-existing behavior since #3889. F1 lifted verbatim
  — not a regression introduced here. Out of scope for a lift PR.
- github-actions bot summary: most items are pre-existing notes
  (TOCTOU residual race, SCRUBBED_CHILD_ENV_KEYS allowlist concern,
  sliceLineRange benchmark threshold) on code the F1 lift moved
  verbatim. One ("httpAcpBridge.ts still has ~3700 LOC") is a false
  positive — the file is 97 LOC after F1. Others are cosmetic
  refactors (extract FIXME to tracking issue, ARCHITECTURE_DECISIONS
  doc system, deprecation timeline) that aren't worth churning the
  lift PR over.

- 44/44 acp-bridge tests pass
- typecheck clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): tighten BridgeFileSystem contract + re-export type from shim

Self-review + code-reviewer agent fold-in, two changes:

1. `cli/src/serve/httpAcpBridge.ts` shim now re-exports
   `BridgeFileSystem` from `@qwen-code/acp-bridge/bridgeFileSystem`
   so the immediate F1 follow-up adapter (in `cli/src/serve/`)
   can import it via the established `./httpAcpBridge.js` path
   like every other daemon-side bridge import does. Without this
   the adapter would need to deep-import from acp-bridge while
   every other serve file goes through the shim — inconsistent.

2. `BridgeFileSystem.readText` + `writeText` JSDoc now spells out
   the two defensive gates the inline proxy carried (non-regular-
   file rejection + 100 MiB buffered-size cap for reads;
   write-then-rename atomicity + dangling-symlink walk-through +
   mode preservation + `0o600` new-file default for writes). When
   a `BridgeFileSystem` is injected, the inline path is FULLY
   bypassed — without the contract spelled out, a future adapter
   author could silently drop the `/dev/zero` / 500 MB log RSS
   defenses the inline path established.

Note on F1 CI: this PR targets `daemon_mode_b_main` but the
`.github/workflows/ci.yml` `pull_request` trigger is scoped to
`branches: main / release/**`, so the main CI workflow (Lint /
Test on Linux/macOS/Windows / CodeQL) does NOT run on this PR.
This is a by-design side effect of the new feature-cohesive
branching strategy — `daemon_mode_b_main → main` periodic merges
will trigger the full CI matrix, providing safety net coverage
before any F-series work lands on `main`. Locally verified:
- 174/174 cli httpAcpBridge tests pass
- 44/44 acp-bridge tests pass
- 735/735 cli serve tests pass
- typecheck clean across acp-bridge + cli

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* test(acp-bridge): cover BridgeFileSystem injection seam + extract shared writeStderrLine (#4319 wenshao review)

Folds in wenshao review on #4319:

1. **[Critical]** zero test coverage for the F1 step 5 `BridgeFileSystem`
   delegation branches in `BridgeClient.writeTextFile` /
   `BridgeClient.readTextFile` and the factory's
   `opts.fileSystem` → constructor positional-arg forwarding.

   New `packages/acp-bridge/src/bridgeClient.test.ts` adds 6 tests
   covering:
   - writeTextFile delegates to injected fileSystem.writeText (inline
     proxy fully bypassed; `fakeFs.writeText` called with the original
     params; `readText` mock not invoked)
   - writeTextFile invalid-path call succeeds purely via the mock
     when fileSystem is injected (proof that the inline `fs.realpath`
     path doesn't run)
   - readTextFile delegates to injected fileSystem.readText
   - readTextFile propagates injection errors to the caller
   - inline-fallback regression guard: write actually hits disk via
     the inline proxy when fileSystem is omitted (real tmp file
     round-trip)
   - same for read

   Why these matter: the 7-arg `BridgeClient` constructor places
   `fileSystem` at the tail as optional. A reordering — or dropping
   the arg from `bridge.ts` factory's `new BridgeClient(..., opts.fileSystem)`
   call — would silently bypass the adapter in production and the
   inline `fs.writeFile` raw-path would run with no audit / trust /
   TOCTOU coverage. The delegation tests would catch that because
   the mock fileSystem would never be invoked.

2. **[Suggestion]** `writeStderrLine` was defined identically in
   `bridge.ts:117` and `bridgeClient.ts:30` (22 call sites across the
   two files). Both consumers live in the SAME `@qwen-code/acp-bridge`
   package, so the original "no reverse-dep on cli" justification
   doesn't apply within the package. Extracted to
   `packages/acp-bridge/src/internal/stderrLine.ts` — a single source
   of truth that future behavior changes (timestamp prefix, log
   level, structured field) can edit once. `internal/` subpath is
   intentionally not in `package.json`'s `exports`, keeping the
   helper package-private. `spawnChannel.ts` deliberately does NOT
   consume it (its stderr writes use `process.stderr.write(prefix +
   line + '\n')` directly because each line carries its own
   `[serve pid=… cwd=…]` line prefix).

- 6/6 new BridgeFileSystem-seam tests pass
- 50/50 acp-bridge total (44 existing + 6 new)
- 174/174 cli httpAcpBridge tests pass (no regression from refactor)
- typecheck + eslint clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* test(acp-bridge): cover defaultSpawnChannelFactory env scrubbing + fix bridge.ts comment refs (#4319 wenshao round 2)

Folds in wenshao review on #4319 round 2 — 1 Critical + 2 Suggestions:

1. **[Critical] spawnChannel.ts has 0 unit tests, security-critical
   paths untested.** Now that `defaultSpawnChannelFactory` is a public
   export of `@qwen-code/acp-bridge`, channels + IDE consumers can't
   rely on cli-package integration tests for env-scrubbing guarantees.

   Refactored the inline env-scrubbing logic into a pure exported
   helper `scrubChildEnv(source, scrubbed, overrides)`. Behavior is
   byte-identical to the pre-extraction inline implementation; the
   factory body now reads:

       const childEnv = scrubChildEnv(
         process.env, SCRUBBED_CHILD_ENV_KEYS, childEnvOverrides);

   Added `packages/acp-bridge/src/spawnChannel.test.ts` with 12 tests
   covering:
   - shallow-clone (no aliasing into live process.env)
   - QWEN_SERVER_TOKEN stripping
   - non-scrubbed vars pass through
   - override-add a new key
   - override-replace an existing key
   - override with undefined deletes the key (PR 14 fix #4247 wenshao R5)
   - override CANNOT re-introduce a scrubbed key (defense in depth)
   - override CANNOT undo the scrub by setting undefined for a scrubbed key
   - override-apply-after-scrub ordering invariant
   - empty overrides equals no overrides
   - multi-key scrub for forward-compat (the WARNING comment on
     SCRUBBED_CHILD_ENV_KEYS anticipates a future sandboxed-agent
     mode expanding the denylist; this verifies the loop already
     handles that)

   The killChild SIGTERM→SIGKILL escalation + STDERR_LINE_CAP_CHARS
   truncation are NOT covered yet — they require either real child
   processes or extensive node:child_process mocking; both are
   orthogonal to the env-scrubbing security guarantees wenshao
   explicitly called out, and can land as a follow-up if anyone
   wants the full surface tested.

2. **[Suggestion] bridge.ts comments referenced a "consolidated re-
   export block earlier in this file" that doesn't exist in acp-bridge
   (only in the cli shim).** Fixed both occurrences (~line 292, ~line
   310) to point at the actual local import + the package barrel
   re-export.

3. **[Suggestion] bridge.ts canonicalizeWorkspace re-export comment
   referenced `./fs/paths.ts`.** Updated to mention the full lift
   chain: extracted to `cli/src/serve/fs/paths.ts` in PR 18, then
   lifted here to `./workspacePaths.ts` in PR 22b/1.

- 12/12 new spawn env-scrub tests pass
- 62/62 acp-bridge total (50 existing + 12 new spawn)
- 174/174 cli httpAcpBridge tests still pass (the factory's inline
  env-scrubbing refactor preserves byte-identical behavior)
- typecheck + eslint clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): fix 14-arg→7-arg typo in test docstring + simplify canonicalizeWorkspace re-export doc (#4319 wenshao round 3)

Folds in 2 of 3 wenshao Suggestions from #4319 round 3:

1. `bridgeClient.test.ts:20` JSDoc said "the 14-arg constructor's
   positional slot" — typo I introduced when writing the test in
   `fbc92bccf`. The same docstring correctly says "the constructor
   takes 7 positional args" at line 25. Updated to "7-arg".

2. `bridge.ts:3461` `canonicalizeWorkspace` re-export JSDoc no longer
   references the historical `cli/src/serve/fs/paths.ts` location.
   Reads cleaner as a present-tense pointer to `./workspacePaths.ts`
   (where the implementation actually lives now post-PR 22b/1).
   Git history covers the lift chain; the docstring should describe
   current state.

DECLINED + tracked separately:

- **[Critical]** `closeSession` + `killSession` use module-scoped
  `channelInfo` instead of `channelInfoForEntry(entry)` — channel-
  overlap edge case can kill the wrong channel. Wenshao explicitly
  notes "pre-existing bug preserved by the lift" — F1's mechanical-
  lift scope shouldn't carry behavior fixes, and the fix needs a
  channel-overlap regression test to land safely. Tracked as #4325.

- 62/62 acp-bridge tests pass (no regression from doc tweaks)
- typecheck + eslint clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): polish from second-pass self-review (cross-platform test + package metadata + dead tombstones)

Five small adoptions from a second-pass code-reviewer agent review on
F1 (no new external comments — pre-emptive cleanup before reviewer
returns):

1. **`bridge.ts:290-313`** — deleted two standalone "InvalidPermission
   OptionError / WorkspaceInit* / McpServer* lifted to bridgeErrors"
   tombstone comments. Pre-22b they were load-bearing (explained why
   the class wasn't `class`-defined inline at that file location).
   Post-F1 the symbols are imported at the top of the file and the
   comments sit between unrelated code (`writeServeDebugLine` /
   `MAX_DISPLAY_NAME_LENGTH` / `DEFAULT_INIT_TIMEOUT_MS`) with no
   anchor. Dead doc — removed.

2. **`README.md`** — `spawnChannel` entry now lists `scrubChildEnv`
   alongside `defaultSpawnChannelFactory` + `killChild` +
   `SCRUBBED_CHILD_ENV_KEYS`. Channels / VSCode IDE consume the
   package barrel so the helper should be visible in the inventory.

3. **`package.json:description`** — refreshed from the PR 22a wording
   ("EventBus, AcpChannel, in-memory channel, PermissionMediator
   interface") to include F1 additions (`createHttpAcpBridge` /
   `BridgeClient` / `defaultSpawnChannelFactory` / `BridgeFileSystem`).
   Visible on `npm view`-style tooling + IDE hover so worth keeping
   current.

4. **`bridgeClient.test.ts:92-115`** — swapped `/proc/no-such-file`
   for `/this/dir/never/exists/file.txt` and reworded the comment.
   `/proc/` is Linux-only; on macOS / Windows the inline proxy's
   dangling-symlink fallback would write through to a path under
   root rather than failing. Test passed regardless (mock assertion,
   not real disk) but the comment overstated portability.

5. **`spawnChannel.test.ts:36`** — added a comment block explaining
   why the test deliberately hand-rolls the SCRUBBED set instead of
   importing the production `SCRUBBED_CHILD_ENV_KEYS`. The
   decoupling is intentional (pure-function parameterized test +
   forward-guard for future denylist expansion) but a naive reader
   would think it's an oversight.

- 62/62 acp-bridge tests pass
- 174/174 cli httpAcpBridge.test.ts pass
- typecheck + eslint + pre-commit hooks clean

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix(acp-bridge): bridge.ts security fold-in from #4297 review (3 issues)

Folds 3 unresolved review comments from the post-merge thread on #4297
(wenshao via qwen-latest agent) into F1 (#4319). All 3 touch
`acp-bridge/src/bridge.ts` — the same file F1 already moves the lifted
factory into — so consolidating here saves opening a separate
follow-up PR and keeps the security narrative in one reviewable
commit. The 2 cross-package fixes (`core/src/memory/const.ts` test
gap + `cli/src/serve/runQwenServe.ts` malformed-context fallback)
will land as their own small PRs after F1 merges.

#### Fix 1 (wenshao Critical, #4297 thread): `fs.unlink(target)`
arbitrary-file-deletion primitive in `verifyParentWithinWorkspace`
'create'-cleanup

After `fs.open(target, 'wx')` creates the empty file at the real
parent, an attacker with local workspace write access can swap the
parent directory for a symlink (`docs/` → `/etc`). The cleanup's
`fs.unlink(target)` re-resolves the TEXTUAL path through the
attacker's freshly-planted parent symlink, deleting whatever file
exists at the external location.

Fix: drop the `fs.unlink(target)` line. The 0-byte file at the
pre-race location is harmless (0 bytes, inside the workspace we'd
already verified) — leaving it over deleting an arbitrary external
file is the right safety trade. Comment block explains the
reasoning so future maintainers don't re-introduce the unlink.

#### Fix 2 (wenshao Critical): `O_TRUNC` arbitrary-file-truncation
primitive in workspace-init 'overwrite' branch

`O_TRUNC` causes the kernel to truncate the file to zero bytes AT
`open(2)` SYSCALL TIME — strictly before `verifyParentWithinWorkspace`
runs. A parent-symlink TOCTOU race between
`canonicalizeExistingAncestor` and this `open()` zeros the file at
the attacker-redirected location (arbitrary-file-truncation
primitive against any file the daemon UID can open). The pre-fix
code's own comment on `verifyParentWithinWorkspace` acknowledged
this as "Acceptable residual posture for the Stage-1 trust model";
wenshao pushed back that arbitrary-file-zeroing exceeds the
Stage-1 trust budget.

Fix: drop `O_TRUNC` from the open flags. Truncation moves to AFTER
`verifyParentWithinWorkspace` succeeds, via `fh.truncate(0)` on the
fd we already hold. fd-based truncate does NOT re-resolve the path
— an attacker swapping the parent symlink after we open can't
redirect the truncation.

#### Fix 3 (wenshao Suggestion): `canonicalizeExistingAncestor`
missing `ELOOP` catch

Circular symlinks in the parent path (`a -> b`, `b -> a`) cause
`fs.realpath` to fail with `ELOOP`. Without catching it, the error
propagates as an unstructured HTTP 500 instead of the typed
`WorkspaceInitSymlinkError` (HTTP 400) the route handler expects
from the workspace-init race-detection family.

Fix: add `'ELOOP'` to the caught error codes alongside `'ENOENT'`
and `'ENOTDIR'`. Walking up the parent chain when ELOOP hits at a
sub-component preserves the existing "walk to the deepest extant
ancestor" contract — the deepest realpath-able ancestor still
dictates the canonical prefix.

#### Why no new tests in this commit

- Fix 1 is a single-line removal: any regression that re-adds the
  unlink would be caught by reviewing the diff; existing 174-test
  `httpAcpBridge.test.ts` integration suite confirms the create-path
  still works (file is created + closed correctly; only the
  attacker-cleanup branch changes).
- Fix 2 is a structural move (truncate from open-time to post-verify);
  the existing overwrite-init integration tests confirm the
  end-to-end behavior is unchanged (file ends up empty after init).
  Adding a TOCTOU race regression test requires controlled
  filesystem-race simulation that exceeds reasonable test infra
  scope for this PR.
- Fix 3 is a one-word addition to an error code list; the
  `canonicalizeExistingAncestor` helper is module-private and the
  integration test for circular-symlink → typed 400 would require
  exporting it OR setting up a real circular-symlink workspace.
  Both routes widen scope beyond the security fix itself; the
  high-level behavior is verifiable by the existing route-error-
  mapping test pattern + diff review.

A follow-up PR can add the integration tests once the security fix
itself has shipped; the immediate priority is closing the
arbitrary-file-deletion + arbitrary-file-truncation primitives.

- 62/62 acp-bridge tests pass
- 174/174 cli httpAcpBridge.test.ts pass
- typecheck + eslint clean

#### Refs

- Original review on #4297 (wenshao via qwen-latest agent), post-
  merge, currently unresolvable on #4297 itself because that PR is
  already MERGED.
- Other 2 #4297 review threads (`const.ts` test coverage,
  `runQwenServe.ts` malformed-context observability) target files
  outside F1's scope and will land as separate follow-up PRs.

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* fix: post-merge Codex P2 fold-in — MCP restart disabled-tools normalization + SDK timeout headroom (#4319)

Folds in 2 P2 findings from a Codex review run on `git diff main...HEAD`
of F1 PR #4319. Both are pre-existing in code merged into
`daemon_mode_b_main` before F1 was created (#4282 PR 17), but they're
tiny tactical fixes (~25 LOC + 1 LOC) on the same integration branch
the same reviewer (wenshao) already engages with, so folding into F1
saves an extra follow-up PR cycle.

#### Fix 1: normalize disabled tool names during MCP restart refresh

`packages/cli/src/acp-integration/acpAgent.ts:1563-1566`

The bootstrap path in `cli/src/config/config.ts:1426-1434` applies a
4-step normalization to `tools.disabled`:
  1. typeof string filter
  2. .trim()
  3. drop empty after trim
  4. dedupe via Set

The MCP-restart refresh path only did step 1, then stored the raw
strings. `ToolRegistry` checks disabled tools with EXACT
`Set.has(tool.name)`, so a tool disabled at boot as `' Foo '` (or
`'Foo\n'`) is no longer matched after `restartMcpServer` and gets
silently re-registered. This contradicts the documented "toggle +
restart" workflow that #4282 PR 17 advertised.

Fix: mirror the bootstrap normalization verbatim before
`setDisabledTools`. Adds 6 lines + a 7-line comment pointing at the
bootstrap reference for future maintainers.

#### Fix 2: add headroom to MCP restart SDK timeout

`packages/sdk-typescript/src/daemon/DaemonClient.ts:102`

The SDK's `MCP_RESTART_DEFAULT_TIMEOUT_MS` was EXACTLY 300_000ms, the
same ceiling the daemon's own `MCP_RESTART_TIMEOUT_MS` uses for the
upper bound on a single MCP rediscovery. For restarts that finish
(or fail with a typed `McpServerRestartFailedError` JSON envelope)
near 300s, the client `AbortSignal` could fire BEFORE the daemon had
finished serializing + transmitting the response, yielding a client
`TimeoutError` even though the daemon was still within its own
budget.

Fix: bump to 330_000ms (10% / 30s headroom over the daemon ceiling).
Comment updated to call out the race + the rationale for the
specific headroom value. Callers needing tighter caps still pass
their own `timeoutMs` to `restartMcpServer`.

#### Why folded into F1 vs separate follow-up PRs

These are post-merge findings on `#4282 PR 17` code, not F1-introduced
regressions. Normally we'd track as separate follow-up issues (mirror
of the #4325 / `channelInfo` decline). But:

- Both fixes are TINY (~25 LOC + ~2 LOC including comment); the bridge
  security fold-in commit `7bd66c6e8` set the precedent of folding in
  small same-branch issues when the cost-benefit favors closing them
  immediately.
- Same reviewer (wenshao via qwen-latest agent) — won't be confused
  by the scope expansion; in fact the original PR 17 commenter is
  also the one who'd review the follow-up issue's fix.
- Both fixes target `daemon_mode_b_main`-only paths (MCP restart route
  added by PR 17 lives on the integration branch).
- Saves opening 2 trivial follow-up issues that would just sit until
  someone picks them up.

#### Verification

- sdk-typescript: 424/424 tests pass (no test hardcoded the old
  300_000 default — only the constant declaration itself referenced it)
- cli acp-integration: 282/282 tests pass (no test exercised the
  exact whitespace-bearing disabled-tools scenario, so no test
  changes were strictly required; a regression test would belong in
  a separate test-coverage PR alongside the const.ts test gap from
  the #4297 unresolved-comment thread)
- typecheck clean across cli + sdk-typescript

🤖 Generated with [Qwen Code](https://github.com/QwenLM/qwen-code)

* docs(acp-bridge): wenshao review round 4 — 3 Suggestion fold-ins (#4319)

1. **bridge.ts:2270 stale line refs in `publishWorkspaceEvent` JSDoc**
   — comment said `permission_resolved at line 1717` (actual: line 682)
   and `broadcastWorkspaceEvent closure at ~line 2127` (actual: line
   1281). Line numbers drifted across the lift commits. Replaced both
   with function-name refs (`in resolvePending`, `declared above in
   this factory body`) that survive future edits.

2. **`ws.ts:613` opaque references in bridgeFileSystem.ts:20 +
   bridgeOptions.ts:267** — no `ws.ts` file exists in the repo; the
   ref came from an internal review thread on PR 18 that future
   readers can't locate. Replaced with a self-contained description
   ("post-PR-18 follow-up thread about BridgeClient's inline fs prox…

Co-authored-by: Greg Shikhman <shikhman@google.com>