Rule: merge a code PR only on a clean Copilot review

Scope: code PRs (the code-ticket workflow).

The Copilot review is the gate, not a formality. Therefore:

• You MUST obtain the review verdict from python3 scripts/await_copilot_review.py <pr-number>, which prints JSON including a clean boolean.
• You MUST NOT call scripts/merge_pr.py unless that JSON reports "clean": true (Copilot approved with no outstanding comments).
• If clean is false, you MUST address every comment, push the fix, re-request the review, and wait again — repeating until it is clean.
• You MUST NOT merge while even one comment is unresolved, even if you judge it unimportant. "I think it's fine" is not clean.

clean is computed deterministically in scripts/await_copilot_review.py (summarize); this rule forbids merging until it is true.