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/implement-category-3-audit/IMPLEMENTATION.md

@@ -1,12 +0,0 @@
-# IMPLEMENTATION.md — Category 3 Audit
-
-## Changes Made
-- `scripts/status.py:698-703`: Replaced "future work" stub with `_audit_category3()` function call
-- `scripts/status.py:605-660`: Added `_audit_category3()` function implementing git-based modification detection
-
-## How It Works
-- Checks `git diff --name-only HEAD` and `git diff --cached --name-only HEAD` for uncommitted changes
-- Excludes files inside task folders (those are legitimate workflow artifacts)
-- If no task is in implement/doc_review phase, all uncommitted changes outside task folders are flagged as violations
-- If active edit tasks exist, changes outside task folders are reported as informational
-- Handles missing .git directory gracefully