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/project-migration/IMPLEMENTATION.md

@@ -1,27 +0,0 @@
-# Implementation: Project Migration Script
-
-## Summary
-
-Created `scripts/migrate-project.sh` to clean up projects that were set up under the old copy-based model. Also updated `prompts/onboarding.md` to detect stale projects and offer migration.
-
-## Changes Made
-
-### `scripts/migrate-project.sh`
-Shell script that:
-1. Scans `{project}/.automaton/` for files that now live in `~/.automaton/`
-2. Files **identical to global** → deleted (framework provides them)
-3. Files **different from global** → moved to `.automaton/extensions/`
-4. Preserves `.agent.md` and `.rules.md` as-is
-5. Reports what was deleted, moved, and kept
-
-### `prompts/onboarding.md`
-Added "Migration Check" section at the end:
-- During onboarding, checks if project has stale framework file copies
-- Identifies files beyond `.agent.md` and `.rules.md`
-- Offers to run `migrate-project.sh` or provides manual instructions
-
-## Files Created
-- `scripts/migrate-project.sh` — migration shell script (125 lines)
-
-## Files Modified
-- `prompts/onboarding.md` — added migration detection section