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-dashboard-read-state/CODE_REVIEW.md

@@ -0,0 +1,17 @@
+# Code Review: fix-dashboard-read-state
+
+## Reviewed Files
+- `automaton/dashboard/core/task.py` (`_state_string_to_task_state()`, `determine_task_state()`)
+
+## Changes
+Added `_state_string_to_task_state()` helper and modified `determine_task_state()` to read `.state` file before falling back to artifact heuristic.
+
+## Analysis
+- **Correctness**: `.state` file is the source of truth per v2.0 framework design, so it should take precedence
+- **Sub-state handling**: `_state_string_to_task_state()` correctly splits on `:` to extract base phase (e.g. `code_review:awaiting_approval` → `CODE_REVIEW`)
+- **Fallback**: Tasks without `.state` files still work via artifact heuristic (backward compatible)
+- **Null safety**: Returns `None` for unrecognized phase strings, which `determine_task_state()` handles by falling through to artifacts
+
+## Verdict: PASS
+
+The fix correctly prioritizes the `.state` file as source of truth while maintaining backward compatibility.