Adds the signaling mechanism for agents to tell crit they're done editing.
The endpoint resets the pending edit counter and signals via a channel that
will be consumed by the batch file-watching logic (Task 3). The `crit go`
subcommand wraps this API call for a cleaner developer experience.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

WatchFile now sends "edit-detected" SSE events (with edit count) on file
changes instead of immediately sending "file-changed". The full
"file-changed" event is deferred until the agent signals round completion
via the roundComplete channel, allowing multiple file edits to be batched
into a single review round.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Extend the Comment struct with Resolved, ResolutionNote, and
ResolutionLines fields. These allow agents to mark comments as resolved
by editing .comments.json directly. The fields use omitempty so they
don't appear in JSON output for unresolved comments.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…oter

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- Only snapshot PreviousContent/PreviousComments on first edit of a round
  (pendingEdits == 0), not on every file change. This ensures the diff
  covers all changes since the round started, not just the last edit.
- Load resolved comments from .comments.json on round-complete so the
  agent's resolved/resolution_note/resolution_lines fields are available
  to the frontend.
- Don't delete .comments.json in ReloadFile — the agent needs it during
  the editing phase. Clean up happens on round-complete instead.
- Re-render document after fetching previousComments so resolved comment
  cards appear at their mapped positions.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- Move "Round #N" and "Show Diff" button to header-right
- Rename button to "Show Diff" / "Show Review"
- Fix diff side labels overlapping content (remove sticky positioning)
- Diff closed by default on new round (user clicks to open)
- Remove .btn-active style, use standard button styling
- Restore round state on browser refresh (fetch /api/previous-round on init)
- Add reviewRound field to Document, expose via /api/previous-round
- Fix bug: SignalRoundComplete now clears comments and resets nextID
  (previously stale comments persisted if agent didn't edit source file)
- Clean up .review.md on round-complete
- Add tests for round increment, comment clearing, and review_round API

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

The review file now contains only the original content + inline comments,
no boilerplate footer. The finish prompt is shorter while keeping the
essential info (review file path, JSON path, crit go command).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>