Archive completed tasks, add cleanup commands, self-documenting dashboard UI

- Archive 79 completed framework-dev tasks from tasks/ -> tasks/complete/
- status.py: add --cleanup-done and --install-cleanup-schedule commands
- Add scripts/automaton-cleanup.sh for periodic task archiving
- Dashboard: rename 'Background' tab -> 'Agent', 'Cleanup' agent -> 'Completed Task Archiver', remove redundant group headers and pill badges, dim inactive agent placeholders
- .rules.md: add Self-Documenting UI Names rule
- New tests: test_cleanup_done.py, expanded test_app.py and test_task.py

tasks/complete/review-textarea/SPEC.md

@@ -0,0 +1,28 @@
+# SPEC: Replace Prompt Dialog with Inline Comment Textarea
+
+## Overview
+
+The review approval flow uses `prompt()` for comments, which is a jarring browser popup. Replace it with a textarea in the detail modal. After submission, close the modal and return to the board.
+
+## Changes
+
+### dashboard.js
+- Add comment `<textarea>` in the detail panel review section
+- `submitReview()` reads from textarea instead of `prompt()`
+- On success, close the modal (`closeDetail()`) instead of re-rendering it
+
+### index.html
+- No structural changes needed (textarea is rendered by JS in the detail panel)
+
+### styles.css
+- Add styles for the comment textarea
+
+## Acceptance Criteria
+- [ ] Review section shows a textarea for optional comment
+- [ ] Clicking Approve/Request Changes submits with textarea content
+- [ ] Modal closes after successful submission
+- [ ] No browser `prompt()` popup
+
+## Notes
+- Textarea is always visible in the review section
+- Comment is optional (can be empty)