- update the watcher start helper to stop any stale watcher instance for the same requested parent build name and remove its old state directory before starting fresh
- document that reused parent build names must not inherit stale cancelled, posted, state.json, or subruns state from older runs
- update the watcher install and design docs so the controller workflow explicitly treats stale reused-build-name state as part of startup cleanup
- update the watcher design and automation guide to treat --categorize as sequential ATVM sub-runs rather than one parent run with internal phases
- document that categorized runs should send one Mattermost status per completed grouped sub-run instead of one parent-only final post
- add a --categorize option to the watcher start helper so categorized mode is explicit in watcher startup
- update the watcher implementation to track categorized sub-runs separately, write per-subrun state, and post each completed grouped run once
- change ATVM status formatting to the approved Markdown-table template with SUMMARY:, HOSTS:, TIMING:, and NOTES:
- document that normal status requests print locally only unless explicitly asked to send to Mattermost
- document Mattermost defaults and posting rules, including only sending after full run completion
- document the controller-side systemd watcher design for future automation
- add the secrets migration/cleanup review doc
- ignore .env.credentials.local in git and reflect the move toward using that local credentials file instead of hardcoded secrets
