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/task-status-reason/SPEC.md

@@ -1,40 +0,0 @@
-# Add Status Reason to Task Display
-
-## Goal
-Show a human-readable explanation of *why* a task is in its current state, fix the pending review count to exclude terminal-state tasks, and replace approve/request-changes buttons with revoke buttons when a review is already submitted.
-
-## Requirements
-
-### R1. Add `status_reason` property to Task
-Add a `status_reason` property on the `Task` dataclass that derives a human-readable explanation from the task's state, artifacts, and verdict status. For example:
-- DONE → "Verdict: PASS"
-- BLOCKED → "Verdict: FAIL — changes required before re-review"
-- BUG_FIND (with IMPLEMENTATION.md) → "Implementation complete — awaiting bug finding"
-- BACKLOG → "No artifacts yet — not started"
-
-### R2. Expose `status_reason` in API responses
-Include `status_reason` in the JSON response for both `/api/tasks` and `/api/task/{name}`.
-
-### R3. Display status reason prominently
-- Show `status_reason` below the status badge in the task detail panel
-- Show `status_reason` on task cards for blocked/bug_find/adv_bug_find states
-
-### R4. Fix pending review count
-The pending review counter in the header currently counts all tasks without a review, including DONE tasks. Fix it to exclude terminal states (done, blocked) so only active tasks count toward pending.
-
-### R5. Replace review buttons with revoke on submitted reviews
-When a task already has an approved review, replace the approve button with "Revoke Approval". When changes are requested, replace with "Revoke Changes". Both send status="pending" to reset the review.
-
-## Acceptance Criteria
-- [ ] `status_reason` property works for all task states
-- [ ] `/api/tasks` responses include `status_reason`
-- [ ] Detail panel shows status reason below the status badge
-- [ ] Task cards show status reason for blocked/bug_find/adv_bug_find tasks
-- [ ] Pending review count excludes done/blocked tasks
-- [ ] Approved tasks show "Revoke Approval" instead of "Approve"
-- [ ] Backend accepts "pending" as a review status
-- [ ] All tests pass
-
-## Non-Goals
-- Not changing the task state machine — revoking a review only resets the review metadata, not the task state
-- Not adding buttons to change task state directly (e.g., send back to planning) — that's a larger feature