Instruments every db.disconnect() and PostgresEngine.disconnect() call
with a JSONL audit record so the next user-reported #1570 cycle gives
us the offender's caller stack instead of the symptomatic
"No database connection" error.

Audit shape (~/.gbrain/audit/db-disconnect-YYYY-Www.jsonl):
  {ts, engine_kind, connection_style, caller_stack[], command, pid}

- src/core/audit/db-disconnect-audit.ts (NEW): the audit writer,
  built on the v0.40.4.0 createAuditWriter cathedral. Captures a
  6-frame stack via new Error().stack so the offender is readable
  without spending stderr noise.
- src/core/db.ts: logDbDisconnect call at the top of disconnect()
  (best-effort; never blocks the real teardown).
- src/core/postgres-engine.ts: same instrumentation in
  PostgresEngine.disconnect() — distinguishes 'module' vs 'instance'
  connection_style so we can tell legitimate worker-pool teardowns
  apart from the load-bearing module-singleton class.
- src/commands/doctor.ts: extends batch_retry_health to surface
  24h disconnect count + most-recent caller stack. Warns when the
  caller frame isn't a known CLI-exit frame (e.g. cli.ts's finally
  block at the end of an op-dispatch). This is the diagnostic that
  tells v0.41.28+ where to apply the real ownership fix.
- test/db-disconnect-audit.test.ts: unit coverage for the audit
  writer + caller-stack capture + JSONL shape.
- test/e2e/db-singleton-shared-recovery.test.ts: real-Postgres
  regression that exercises the singleton-null path end-to-end.

Refs #1570

…1.27.0)

withRetry gains an opt-in reconnect callback that fires between the
isRetryableConnError classification and the inter-attempt sleep.
PostgresEngine.batchRetry injects this.reconnect() — race-safe via
the existing _reconnecting guard, handles module and instance pools.

Closes the production loss reported in #1570: dream cycles on Supabase
no longer drop ~150 link rows per cycle when the singleton goes null
mid-batch. The retry now rebuilds the connection between attempts so
the second try has somewhere to write to.

- src/core/retry.ts: WithRetryOpts gains `reconnect?: () => Promise<void>`.
  Awaited in the catch branch. onRetry is also now awaited (back-compat-
  safe: every existing in-tree caller is a sync arrow). Reconnect
  failures propagate as the real cause — replaces the symptomatic
  "No database connection" error with whatever the connect() throw
  was, so operators see the truth.
- src/core/postgres-engine.ts:batchRetry — injects
  `reconnect: () => this.reconnect()`. Covers all 9 batch-retry call
  sites (addLinksBatch, addTimelineEntriesBatch, upsertChunks, plus
  the 6 caller-supplied auditSite labels in extract / sync / reindex).
- test/core/retry-reconnect.test.ts: 8 hermetic cases pinning the
  contract — reconnect fires before sleep, only on retryable errors,
  back-compat when omitted, signal-aborted bypasses reconnect,
  onRetry is awaited, full success path end-to-end.

The deeper bug (who's calling disconnect mid-cycle) is left
unaddressed in this commit by design — the diagnostic instrumentation
in the prior commit will tell us in the next production run.

Refs #1570

Closes the silent 'No database connection' tail-end errors after
gbrain capture / put_page: the facts:absorb fire-and-forget queue
sometimes outlived the CLI process's connection lifetime, so absorb
attempts after engine.disconnect() landed in stderr as the
GBrainError shape.

- src/core/facts/queue.ts: new drainPending({timeout: 1000}) method
  distinct from shutdown(). Stops accepting new enqueues, awaits
  in-flight settle, bounded by timeout, returns count of unfinished.
  Semantically different from shutdown() (which aborts in-flight)
  so the symptom — drop work that hasn't started yet but let
  in-flight work finish — matches what CLI exit actually needs.
- src/cli.ts: op-dispatch finally block awaits the drain BEFORE
  engine.disconnect(). Bounded 1s. Opt-out env GBRAIN_NO_FACTS_DRAIN
  for callers that don't enqueue (keeps fast-exit paths fast).
  Mirrors the v0.41.8.0 awaitPendingLastRetrievedWrites pattern.
- test/facts-queue-drain-pending.test.ts: 6 hermetic cases — empty
  drain returns immediately, single in-flight settles, timeout
  bounds wait, shutdown-after-drain is idempotent, post-drain
  enqueues are dropped, signal-aborted skips waiting.

Refs #1570

…v0.41.27.0

Master shipped v0.41.26.1 (#1572 lock-renewal cathedral) during this
branch's review cycle. Merging it in:

- VERSION stays at 0.41.27.0 (still the next available slot above
  master's 0.41.26.1 — neither side claimed 0.41.27.0)
- CHANGELOG.md: my v0.41.27.0 entry on top; master's v0.41.26.1 entry
  preserved verbatim below
- TODOS.md: my v0.41.27.0 #1570 follow-ups (forward-references bumped
  to v0.41.28+); master's v0.41.26.1 lock-renewal follow-ups preserved
- package.json: synced to 0.41.27.0

No source-file conflicts — master's lock-renewal work is in
src/core/audit/lock-renewal-audit.ts (new), src/core/minions/worker.ts
(modified), and a handful of audit/test files. None overlap with the
#1570 surface (retry.ts, facts/queue.ts, db.ts, postgres-engine.ts).

README.md: added troubleshooting entry for the v0.41.27.0 retry-reconnect
+ facts:absorb drain fix (closes #1570), pointing operators at
`gbrain doctor --json` to find the offending disconnect caller.

CLAUDE.md: extended `src/core/retry.ts` entry with the new optional
`reconnect` callback (v0.41.27.0); added two new Key Files entries for
`src/core/audit/db-disconnect-audit.ts` (the diagnostic half of the
"instrument first, fix later" pivot) and `FactsQueue.drainPending`;
extended `doctor.ts:checkBatchRetryHealth` entry with the in-place
extension that surfaces 24h disconnect-call count.

llms-full.txt: regenerated to absorb CLAUDE.md edits.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Master shipped v0.41.27.0 (#1573 git-aware sync_freshness) claiming the
same slot. Rebump to the next available version.

- VERSION + package.json → 0.41.28.0
- CHANGELOG.md: my entry header + in-entry refs 0.41.27.0 → 0.41.28.0
- TODOS.md: my #1570 follow-up section header + body refs bumped

Master shipped v0.41.27.0 (#1573 git-aware sync_freshness check) which
claimed the version slot this branch originally targeted. This branch
already rebumped to v0.41.28.0 in the prior commit; merging master in:

- VERSION stays 0.41.28.0 (next slot above master's 0.41.27.0)
- CHANGELOG.md: my v0.41.28.0 entry on top; master's v0.41.27.0 entry
  preserved verbatim below
- package.json: synced to 0.41.28.0
- src/commands/doctor.ts, CLAUDE.md, llms-full.txt: auto-merged
  (master's sync_freshness check + my batch_retry_health disconnect
  audit extension both land; no overlap)
- New from master: src/core/git-head.ts + test/core/git-head.test.ts

No #1570-surface conflicts — master's sync_freshness work is orthogonal
to the retry/facts/disconnect-audit changes.

…ard fix)

Both files failed on CI shards 1 and 8 under the cross-file gateway-state
leak class (CLAUDE.md "Test-isolation lint and helpers"). The v0.41.28.0
merge reshuffled the weight-based shard bin-packing, landing a
gateway-mutating sibling ahead of these two victims in the same `bun test`
process.

Mechanism:
- put-page-provenance: put_page embeds via the gateway. A sibling left
  the gateway configured with OpenAI + the CI placeholder `sk-test`
  (captured at configureGateway time, survives the withEnv restore as
  cached gateway state). put_page's embed then fired against live OpenAI
  and 401'd. The bunfig legacy-embedding preload's beforeEach only
  re-applies legacy when the gateway was RESET — it does NOT correct a
  sibling that configured a different LIVE config.
- embedding-dim-check: initSchema builds the content_chunks vector column
  at the gateway's configured dim. A sibling leaking ZE/1280 made the
  column 1280-d, so `expect(dims).toBe(1536)` failed.

Fix (victim-side pinning, the escape hatch the preload documents):
- Both: configure the gateway explicitly in beforeAll BEFORE initSchema
  (OpenAI/1536), resetGateway() in afterAll so neither leaks onward.
- put-page-provenance also stubs the embed transport via
  __setEmbedTransportForTests so embed is deterministic and offline; a
  dummy OPENAI_API_KEY is supplied in the gateway env because
  instantiateEmbedding builds the OpenAI client (key check) BEFORE the
  stubbed transport is reached — the stub then intercepts the actual
  call so the key never leaves the process.

Verified: CI shards 1 (1337 pass) + 8 (905 pass) green with
OPENAI_API_KEY unset, plus adversarial sibling orderings (gateway.test /
doctor-ze-checks preceding). Typecheck + check-test-isolation clean.