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/hook-install-process/BUG_REPORT.md

@@ -1,10 +0,0 @@
-# Bug Report: hook-install-process
-
-## Summary
-No code bugs found. Process issue: the task was created after implementation was complete, which is a violation of the framework's own process. Otherwise, the changes are minimal and correct.
-
-## Bugs Found
-None.
-
-## Score
-+10