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/review-textarea/SPEC.md

@@ -1,28 +0,0 @@
-# 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)