Add post-review gate for NOTE/WARNING findings before merge

[sebastientaggart]

When the AI review approves with non-blocking findings (NOTE/WARNING items), the flow now pauses and asks the user whether to address findings first or merge now — instead of merging immediately. Clean reviews with no findings still auto-merge.

Issue #94

[sebastientaggart]

Review Summary

Verdict: APPROVE

Findings

No issues found. Code looks correct and follows project conventions.

The new gate logic correctly distinguishes clean approvals (auto-merge) from approvals with non-blocking findings (pause and ask). The "merge now" path properly chains into Step 9's follow-up issue offer, and the "address" path correctly halts without merging. All five files (source template + four adapter copies) carry identical changes with appropriate hash updates.