Backports upstream PR QwenLM#3525 + extends the per-stream context to also
cover our fork's <think>-tag parser state.

Bug: every caller of Config.getContentGenerator() — foreground turns,
fork subagents, run_in_background subagents, ACP concurrent Agent calls
(after QwenLM#3463) — shared a single OpenAIContentConverter, which held the
StreamingToolCallParser as an instance field. Concurrent streams
corrupted each other's tool-call buffers, surfacing as NO_RESPONSE_TEXT.

Fix:
- New ConverterStreamContext interface holds toolCallParser, thinkBuffer,
  inThinkTag — one per stream.
- createStreamContext() factory replaces resetStreamingToolCalls().
- convertOpenAIChunkToGemini(chunk, ctx) and processThinkChunk(chunk, ctx)
  thread the context through every parser/think-buffer access.
- ContentGenerationPipeline.processStreamWithLogging creates one context
  at stream entry. The error path no longer manually resets — the
  context is GC'd when the generator unwinds.

Our protoInternal recovery-note logic is preserved on the new shape.

Note: upstream's follow-up QwenLM#3550 (full stateless converter refactor) is
deferred — it's hygiene without a functional bug; QwenLM#3525 alone fixes
the concurrency race.

Tests:
- New createStreamContext describe replaces resetStreamingToolCalls suite
- Streaming <think> tests use a per-test context
- pipeline.test.ts mock updated to match the new API
- pipeline.concurrent.test.ts (from upstream commit 38edd9d)
  drives two real concurrent streams and asserts neither corrupts the
  other's tool-call output (positive control: pre-fix, this test fails
  with exactly the user-reported bug shape).

Refs upstream QwenLM#3516, QwenLM#3525.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

…#3304)

When switching models mid-session, reasoning_content fields from
thinking-capable models leaked into API requests sent to the new
provider, causing 422 errors on strict OpenAI-compatible endpoints.

Call stripThoughtsFromHistory() in handleModelChange() so thought parts
are removed before the next request is built for the new model.

Backport of upstream QwenLM#3505. Propagates MAX_TOKENS truncation from
subagent responses into tool requests and rejects truncated edit calls
before schema validation can surface misleading missing-parameter errors.

Adapted to our fork's coreToolScheduler.ts which already had the
truncation rejection block — kept both, dropped the unused
clearRetryCountsForTool() call (we don't have that retry-counter
machinery yet).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

… catch-alls (QwenLM#3467)

Backport of upstream QwenLM#3467. A permission rule with unbalanced parens
was silently parsed with specifier: undefined, causing matchesRule to
treat it as a catch-all. For deny rules this blocked all commands; for
allow rules a typo could silently auto-approve everything.

- Adds an invalid flag to PermissionRule
- parseRule marks unbalanced-paren rules as invalid
- matchesRule short-circuits invalid rules to never match
- parseRules / addSession*Rule / addPersistentRule warn on malformed input
- listRules filters invalid rules from /permissions UI

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

…e sessions (GH#3579)

The test from upstream QwenLM#3304 backport assumed an in-place qwen-oauth
model switch path that our fork doesn't have; the source-side fix in
config.ts (stripThoughtsFromHistory call in handleModelChange) is
preserved. Coverage will be re-added when the fork's switch flow
stabilizes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>