Suppress harmless watcher reset-failed noise in ATVM updates

- update the ATVM AGENTS guidance so expected  output is not called out in routine run updates
- update the ATVM automation guide to mention reset-failed output only when it actually blocks watcher startup or matters for debugging
- add a 2026-03-26 run learning recording that this reset-failed output is normal low-signal noise during successful watcher startup

atvm/AGENTS.md

@@ -65,6 +65,7 @@ This file defines how to operate and maintain the ATVM workspace in `/home/aw/co
 - For host-level test detail and failed-test investigation, use `/root/cdc-e2e-cyp-12.17.4/cypress/cmcReporter`, especially `logs/`, `xml/`, and `mochawesome/`.
 - If the operator asks for ATVM run status without mentioning Mattermost, respond locally only and do not post externally.
 - If the operator asks to send ATVM run status to Mattermost, use `MATTERMOST_ATVM_WEBHOOK` and `MATTERMOST_ATVM_CHANNEL` from `/home/aw/code/cds/.env.credentials.local` by default and send the final status only after the run has fully completed, whether the run passed or failed.
+- Do not call out expected, harmless `systemctl reset-failed ... unit not loaded` output in routine run updates; mention it only if it blocks startup or matters for debugging.
 - Treat `docs/automation/examples.md` as reference-only, not default operator intent.
 - Put reusable workflow rules in `guide.md` files.
 - Put dated lessons only in `run-learnings.md` files.