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/task-status-reason/ADVERSARIAL_BUG_REPORT.md

@@ -1,35 +0,0 @@
-# Adversarial Bug Report: task-status-reason
-
-## Summary
-Deep-dive audit found 3 subtle issues: misleading red border on bug_find cards, redundant verdict parsing, and no status_reason propagation to subtasks.
-
-## Bugs Found
-
-### Bug 1: Red error border on bug_find task cards is misleading
-- **Severity**: Low
-- **Location**: `automaton/dashboard/html/styles.css` — `.task-card-reason` rule
-- **Description**: The `.task-card-reason` CSS uses `border-left: 2px solid var(--error)` for all three states (blocked, bug_find, adv_bug_find). But `bug_find` and `adv_bug_find` are normal workflow states, not errors. A green or neutral border would be more appropriate for non-terminal states.
-- **Reproduction**: Open any task in bug_find or adv_bug_find state — the reason banner shows a red border suggesting something is wrong, when it's expected behavior.
-- **Suggested Fix**: Use `var(--warning)` for bug_find states and reserve `var(--error)` for blocked only.
-
-### Bug 2: Redundant verdict parsing on every status_reason access
-- **Severity**: Low
-- **Location**: `automaton/dashboard/core/task.py:136-175` — `status_reason` property
-- **Description**: `status_reason` calls `parse_verdict_status()` again for BLOCKED/DONE tasks, even though `determine_task_state()` already parsed the verdict to classify the state. For DONE, it doesn't re-parse (just returns "Verdict: PASS"), but for BLOCKED it re-reads the verdict content and re-parses. This is redundant but cheap given the small number of tasks.
-- **Reproduction**: Every time the dashboard renders, BLOCKED tasks trigger a second verdict parse just for the display string.
-- **Suggested Fix**: Cache the parsed verdict status on the Task object during `discover_tasks()`, e.g., a `_verdict_status` field that `status_reason` can reference instead of re-parsing.
-
-### Bug 3: Subtask state not visible in detail panel reason
-- **Severity**: Low
-- **Location**: `automaton/dashboard/html/dashboard.js:236-241` — subtask list in detail panel
-- **Description**: Subtasks in the detail panel show only a verdict pass/fail indicator. Unlike parent tasks, blocked subtasks don't display their status_reason in the list. A blocked subtask just shows "✗" next to its name with no explanation of why.
-- **Suggested Fix**: For blocked subtasks, include the subtask's verdict status (FAIL/NEEDS_REVIEW) in the list item, or hover tooltip with the reason.
-
-### Bug 4: Fallthrough status_reason never reached, masks missing states
-- **Severity**: Low
-- **Location**: `automaton/dashboard/core/task.py:175`
-- **Description**: The fallthrough `return f"In {self.state.value} phase"` is dead code — every TaskState value is covered by explicit branches. If a new state is added (e.g., INTEGRATION_TEST), no compile-time error occurs and a vague message is shown. Contrast with Python enums which have no exhaustiveness checking.
-- **Suggested Fix**: Add `# pragma: no cover` or raise/log a warning if a new state goes unhandled.
-
-## Score
-+3