v1.7.0 active: bounded supervised dispatch, review, and escalation

[jeffhuber]

Part of #1096.

Goal

Enable bounded supervised mutation after the shadow Operator has met its soak criteria.

Dependencies

Requires a successful shadow soak and all foundation PRs.

Scope

• Approved issue intake and builder dispatch.
• Exact-head peer review orchestration, finding disposition, and fix-round handling.
• GitHub status/label/comment actions and Slack owner escalation under explicit budgets.
• Stale-head, contributor exclusion, author-never-gates, retry, concurrency, spend, and owner-action controls.
• Manual merge remains the pilot default.

Acceptance criteria

• Every mutation is preceded by a durable intent and followed by response reconciliation.
• Exceeded budgets, uncertain results, policy conflicts, or missing authority stop for owner action.
• A restart during dispatch, review, fix round, or escalation does not duplicate mutations.
• The Operator cannot merge under the default pilot policy.
• One bounded end-to-end delivery completes with the human approving merge.

Code Mower delivery

One focused PR with failure-injection fixtures, policy tests, canonical runbook updates, and independent exact-head review. Live mutation requires explicit pilot configuration after merge.