## Summary

Adds MCP operations for reporting task starts, blockers, pull requests, completion, and revision requests. Lifecycle activity is persisted separately from implementation and pull request state, replayed idempotently, retained across revision requests, and broadcast to connected clients.

## What changed

- Adds start_task, block_task, report_pr, complete_task, and request_revision MCP tools with validated arguments and idempotency keys. - Adds lifecycle transition rules for dependency readiness, blockers, repository-owned pull requests, completion summaries, and revision release. - Persists task progress and prior execution history in plan snapshots while exposing implementation state separately from pull request delivery state. - Broadcasts accepted lifecycle changes through the plan protocol and supports the same transitions for live rooms and persisted rooms.

## How to test

- bun test — 698 unit tests passed, including MCP and lifecycle transition coverage. - bun run types — type checks passed. - bun run ci — formatting and lint checks passed. - git diff --check — whitespace checks passed. - Source review — all ten lifecycle acceptance criteria were checked against the implementation and protocol coverage. - bun run e2e — the browser suite was attempted but Chromium could not launch because the sandbox denied Mach rendezvous registration; no browser result was recorded.

## Notes

- Stacked on [Claim an approved implementation graph through MCP](https://github.com/githubnext/chopin/pull/47), which should be reviewed and merged first. - This change is backend and protocol focused; browser rendering for lifecycle activity is deferred.

Task: `active/018-report-implementation-pr-progress.md`