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/reconcile-dashboard-spec/IMPLEMENTATION.md

@@ -0,0 +1,18 @@
+# Implementation: Reconcile Dashboard Spec with Web Implementation
+
+## Summary
+Updated the dashboard specification and documentation to reflect the actual web-based implementation, and removed the vestigial TUI theme module.
+
+## Files Changed
+- `tasks/dashboard-spec.md` — rewritten for web dashboard
+- `automaton/dashboard/README.md` — removed `q` quit shortcut, updated theme description, removed themes.py/pyproject.toml from architecture diagram
+- `automaton/dashboard/html/index.html` — fixed help modal (`t` = cycle themes, removed `q` quit)
+- `automaton/dashboard/themes.py` — deleted
+
+## Verification
+- `grep -i "terminal\|TUI\|ANSI\|arrow key\|resizable" tasks/dashboard-spec.md` returns no inappropriate matches.
+- `python -m automaton.dashboard` still starts and serves `/`.
+
+## Decisions
+- Web dashboard is canonical; TUI-specific acceptance criteria removed.
+- `themes.py` was a stub for ANSI themes and is no longer needed.