fix: stop hook warnings when quality gates are disabled

[tmustier]

Summary

• distinguish hook enablement from the presence of an enqueue callback in leader inbox polling
• only enqueue hook events and qualify completion copy when hooks are actually enabled
• add smoke coverage for both the per-task and batch-complete notification paths

Testing

• npm run typecheck
• npm run lint
• npm run smoke-test

[tmustier]

Findings

No substantive findings. The change correctly decouples “hooks are wired” from “hooks are enabled,” updates both all-done notification paths, and adds smoke coverage for the disabled-hooks edge case in both per-task and batch-complete leader messages.

Verdict

correct — no P0-P2 issues found; the fix addresses the reported root cause without introducing an obvious regression, and the added tests cover the key notification paths.