bug: quality gate dispatched before Copilot review completes

[microsasa]

Problem

The orchestrator dispatches the quality gate as soon as it sees CI green + 0 open threads. But Copilot review may not have completed yet — it runs asynchronously after CI. This means:

1. Quality gate evaluates and approves the PR
2. Copilot review finishes and adds new comments
3. The APPROVE review is now stale — it was based on pre-review state
4. Auto-merge may proceed despite unresolved threads (mitigated by required_conversation_resolution: true in branch protection, but the stale approval persists)

Example

PR #172: quality gate dispatched at 07:23 while Copilot was still reviewing. QG approved, then Copilot posted a new comment at 07:25. The approval was based on stale state.

Impact

• Wasted quality gate runs (approves then new comments appear)
• Stale APPROVE reviews persist because dismiss_stale_reviews: false
• Could lead to merges with unaddressed review comments if branch protection is ever relaxed

Fix options

1. Orchestrator checks for Copilot review before dispatching QG — verify copilot-pull-request-reviewer has submitted a review on the latest commit
2. Quality gate agent checks for pending reviews — look at whether Copilot review is complete before evaluating
3. Dismiss stale reviews on new pushes — set dismiss_stale_reviews: true so responder pushes invalidate the QG approval (but this affects all reviews, not just QG)

Related

• Quality gate never fires on clean PRs — orchestrator missing happy path #168 (quality gate dispatch)
• bug: orchestrator dispatches responder twice from duplicate triggers #164 (duplicate triggers)