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/standardize-task-path-conventions/IMPLEMENTATION.md

@@ -1,25 +0,0 @@
-# Implementation: Standardize Task Path Conventions
-
-## Summary
-Updated all prompts under `prompts/` to use the canonical task path `{project}/.automaton/tasks/{task-name}/` instead of the deprecated `{project}/tasks/{task-name}/`.
-
-## Files Changed
-- `prompts/decompose.md`
-- `prompts/test_design.md`
-- `prompts/doc_review.md`
-- `prompts/workflow.md`
-- `prompts/referee.md`
-- `prompts/adversarial_bug_find.md`
-- `prompts/research.md`
-- `prompts/design.md`
-- `prompts/implement.md`
-- `prompts/bug_finder.md`
-- `tests/test_prompt_paths.py` (new regression test)
-
-## Verification
-- `rg "\{project\}/tasks/\{task-name\}" prompts/ templates/` returns no matches.
-- `python -m pytest tests/test_prompt_paths.py -v` passes (27 tests).
-
-## Decisions
-- Templates under `templates/tasks/` did not contain legacy paths.
-- The regression test lives in `tests/test_prompt_paths.py` and will fail CI if a legacy path is reintroduced.