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/changelog/BUG_REPORT.md

@@ -0,0 +1,16 @@
+# Bug Report: Changelog and Release Notes Process
+
+## Methodology
+Reviewed CHANGELOG.md and .rules.md entries.
+
+## Acceptance Criteria
+| # | Criterion | Result |
+|---|-----------|--------|
+| 1 | CHANGELOG.md exists with [unreleased] header | ✅ |
+| 2 | .rules.md mentions changelog updates | ✅ |
+| 3 | Format clean enough for release notes | ✅ |
+
+## Findings
+None.
+
+## Verdict: PASS