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/state-file-enforcement/ADVERSARIAL_BUG_REPORT.md

@@ -0,0 +1,13 @@
+# Adversarial Bug Report: State File Enforcement
+
+## Deep Review
+The .state file format and transition rules are robust. Approval sub-states create a hard gate that cannot be bypassed via `--transition`. Atomic writes via tmp+rename prevent corruption on crash.
+
+## Potential Issues
+1. **Race condition on create**: Two concurrent `--create-task` calls for the same name could both pass the "doesn't exist" check before one creates the directory. The atomic rename pattern mitigates this for .state writes but not for `mkdir`.
+
+2. **Manual .state tampering**: A user or agent could directly edit `.state` to write an invalid phase name. `status.py` handles this ("Unknown phase" error), but the error path could be clearer about what phases are valid.
+
+3. **Stale .state after crash**: If an agent crashes after producing an artifact but before transitioning `.state`, the `.state` lags behind artifacts. The artifact heuristic fallback in `--audit` Category 2 catches this, but it's a recovery scenario not a normal path.
+
+## Verdict: PASS — no security or logic flaws that would compromise enforcement.