# Compact Status - 2025-12-06

**Focus**: Fix TOCTOU race condition in spawn delay, code review triage, PR #38 merge

**Key Accomplishments**:
1. Fixed spawn burst TOCTOU race with `withSpawnLock()` promise-chain mutex
2. Triaged 16 code review findings (3 fixed, 12 dismissed as false positives)
3. Merged PR #38 with handler decomposition + spawn serialization fix

**Critical Decisions**:
- Promise-chain mutex over external library (lightweight, sufficient)
- Dismiss JSDoc/private-method-test suggestions (violates project principles)
- Keep sequential event emission (ordering guarantees required)

**Next Priority Actions**:
1. Update EVENT_FLOW.md with spawn serialization documentation
2. Upgrade MCP SDK to fix DNS rebinding vulnerability (>= 1.24.0)
3. Fix outdated line references in TASK_ARCHITECTURE.md

**Critical Issues**:
- None blocking
- HIGH: MCP SDK vulnerability needs upgrade (tracked in issue #31)

**Key Files Modified**:
- `src/services/handlers/worker-handler.ts` - Spawn mutex implementation
- `src/services/handlers/dependency-handler.ts` - Type safety fixes
- `docs/architecture/HANDLER-DECOMPOSITION-INVARIANTS.md` - New doc + updates
- `tests/unit/services/handlers/worker-handler.test.ts` - 19 new tests
- `tests/unit/services/handlers/dependency-handler.test.ts` - Characterization tests

**Context Notes**:
The TOCTOU race in `processNextTask()` allowed spawn bursts even with delay check. The mutex ensures only one spawn runs at a time - delay is defense-in-depth. Never remove `withSpawnLock()`. Code review agents don't understand our patterns - most "issues" were false positives.

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*Quick summary of [full status](./../2025-12-06_2256.md)*
