feat(plan-lifecycle)!: bound reviews and default PR landing

[DocksDocks]

What changed

• Bound code-review convergence to one repair re-review while allowing advisory-only passes.
• Default routine plan publication and passed-review landing to commit, normal push, and a closing pull request.
• Require a fresh two-choice confirmation only before default-branch merge.
• Verify one merge-base candidate, pull-request diff parity, CI policy, and the reviewed head SHA.

Review order

1. 4b11871 implements the separately reviewed issue Make code-review pass cover advisory-only rounds #18 convergence contract.
2. 6aafb47 implements the reviewed issue Complete the reviewed lifecycle landing cutover #20 landing cutover and plan-review repair.

Verification

• node scripts/tests/plan-skill-phases.mjs
• node scripts/ci.mjs

Closes #18
Closes #20
Refs #19