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/spec-in-detail/SPEC.md

@@ -0,0 +1,19 @@
+# SPEC: Display SPEC.md Content in Task Detail Panel
+
+## Overview
+
+The task detail panel shows verdict and bug report content but not the task's SPEC.md. Users need to see the specification when reviewing a task.
+
+## Changes
+
+- Add `spec_content` field to API responses (`_serve_tasks`, `_serve_task`)
+- Display SPEC.md content in the detail panel under a "Specification" section
+
+## Acceptance Criteria
+
+- [ ] SPEC.md content appears in detail panel
+- [ ] API serves `spec_content` for all tasks
+
+## VERDICT
+
+PASS — implemented in commit 01d8451