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/artifact-badges/SPEC.md

@@ -1,20 +0,0 @@
-# SPEC: Show Artifact Badges on Pending Review Tasks
-
-## Overview
-
-Tasks pending review don't show what artifacts were produced. Card should display compact artifact badges (SPEC.md, DESIGN.md, etc.) so reviewers know what needs review at a glance.
-
-## Changes
-
-- Add `ARTIFACT_LABELS` mapping
-- Show artifact badges on cards when review status is pending or changes_requested
-- CSS for `.task-card-artifacts` and `.artifact-badge`
-
-## Acceptance Criteria
-
-- [ ] Pending review tasks show artifact badge chips on their card
-- [ ] Approved/completed tasks do not show artifact badges
-
-## VERDICT
-
-PASS — implemented in commit 75cb4a1