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/actionable-phase-guidance/ADVERSARIAL_BUG_REPORT.md

@@ -0,0 +1,14 @@
+# Adversarial Bug Report — actionable-phase-guidance
+
+## Attack Vectors
+1. **Empty state**: What happens for an unknown/unexpected state value?
+2. **HTML injection**: Could guidance text contain user-controlled content that escapes sanitization?
+3. **Empty guidance**: Does the frontend handle missing/incomplete guidance gracefully?
+
+## Findings
+- Unknown states fall through to a generic return — safe, no crash
+- Guidance text is static (no user content), so injection is not a concern
+- Frontend checks `task.phase_guidance` truthiness before rendering the guidance section — safe
+
+## Verdict
+No vulnerabilities found. The implementation is defensive against all checked attack vectors.