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-guard-plugin-derailment/IMPLEMENTATION.md

@@ -0,0 +1,10 @@
+# IMPLEMENTATION.md — Fix Guard Plugin Derailment
+
+## Changes Made
+- `plugins/automaton-guard/plugin.ts:60-65`: Replaced `client.chat()` injection with `throw new Error()`
+
+## How It Works
+- When an edit is blocked, the guard now throws an error instead of injecting synthetic user messages
+- This prevents derailing the agent's context mid-operation
+- The harness handles the error cleanly without contaminating message history
+- The error message still includes actionable instructions for creating/transitioning tasks