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/SPEC.md

@@ -0,0 +1,25 @@
+# SPEC: Reconcile Dashboard Spec with Web Implementation
+
+## Goal
+Eliminate the mismatch between `tasks/dashboard-spec.md` (which describes a terminal TUI) and the actual web-based dashboard implementation.
+
+## Requirements
+1. Rewrite `tasks/dashboard-spec.md` acceptance criteria to describe the implemented web dashboard.
+2. Update `automaton/dashboard/README.md` help table so shortcuts match the web UI:
+   - `t` cycles themes, not waves.
+   - `q` is documented as browser-only (or removed).
+3. Update `automaton/dashboard/html/index.html` help modal to match the README.
+4. Delete `automaton/dashboard/themes.py` (vestigial ANSI theme stub).
+
+## Acceptance Criteria
+- [ ] `tasks/dashboard-spec.md` contains no TUI-only requirements (ANSI, arrow keys, terminal width, resizable panels).
+- [ ] `README.md` and help modal agree on keyboard shortcuts.
+- [ ] `themes.py` is removed.
+- [ ] `python -m automaton.dashboard` still starts and serves `/` and `/api/tasks`.
+
+## Non-Goals
+- Converting the web dashboard to a TUI.
+- Adding new dashboard features.
+
+## Stop Condition
+When all acceptance criteria are met, output "CONTRACT_MET".