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/fix-migrate-find-precedence/SPEC.md

@@ -0,0 +1,18 @@
+# Spec: fix-migrate-find-precedence
+
+## Problem
+`scripts/migrate-project.sh:108` has a `find` command without parentheses:
+```
+find "$PROJECT_AUTOMATON" -maxdepth 1 -type f -name "*.md" -o -name "*.sh" -print0
+```
+Without parens, `-print0` only applies to the `.sh` branch. `.md` files are found but never printed, so customized `.md` files are silently skipped during migration.
+
+## Fix
+Add parentheses around the `-o` group:
+```
+find "$PROJECT_AUTOMATON" -maxdepth 1 -type f \( -name "*.md" -o -name "*.sh" \) -print0
+```
+
+## Acceptance Criteria
+- Both `.md` and `.sh` files are processed by the migration loop
+- `bash -n scripts/migrate-project.sh` passes