# Review by Staff Security Engineer (Round 3)

## Staff Security Engineer — Review Complete

**All 15 tests pass.** All 7 functional requirements implemented. +373/-1 lines across 4 source files, 5 commits.

### Security Assessment: No concerns.

| Check | Status |
|---|---|
| No new OAuth scopes | ✅ `reactions:write` already covers `reactions.remove` |
| No user-controlled input in API calls | ✅ All emoji names are hardcoded string literals |
| Fault isolation | ✅ Each API call in independent try/except |
| Exception propagation | ✅ `remove_reaction()` doesn't swallow — callers decide |
| No secrets in diff | ✅ Verified clean |
| No new dependencies | ✅ Zero new imports/packages |
| Audit logging | ✅ Debug-level with `exc_info=True`, distinct messages |

**Non-blocking observations:**
1. Tests simulate completion logic rather than exercising actual `QueueExecutor` code path — pragmatic given nested class complexity
2. Broad `except Exception` catches are consistent with existing codebase convention

---

VERDICT: approve

FINDINGS:
- [src/colonyos/slack.py]: `remove_reaction()` correctly does not swallow exceptions, delegating error policy to callers. No new attack surface.
- [src/colonyos/cli.py]: Both completion paths use hardcoded emoji literals — no user-controlled input reaches `reactions_remove`. Each API call independently wrapped in try/except.
- [tests/test_cli.py]: Tests replicate the exact call sequence from cli.py rather than testing the actual QueueExecutor code path. Acceptable trade-off.
- [tests/test_slack.py]: `test_propagates_exception` verifies the helper doesn't swallow errors. Protocol test correctly updated.

SYNTHESIS:
This is a clean, minimal change with zero security concerns. 19 lines of production code, one new API wrapper, two identical completion blocks, all with proper failure isolation. No new scopes, no user input in API calls, no secrets, no new dependencies. The critical completion signal is never gated on cosmetic cleanup. Ship it.