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/docs/automation/guide.md

@@ -50,6 +50,8 @@ Run ATVM CMC automation tests on the designated automation VM without unintended
   - if the child build id label does not match the actual host/spec being executed, report the grouped run using the inferred host-based group instead of the raw child build id label
   - it must not wait and replace those with one single parent-only post
 - After execution, report immediate success/failure only.
+- Do not include expected, harmless `systemctl reset-failed ... unit not loaded` output in routine run-start confirmations.
+- Mention `reset-failed` output only when it prevents watcher startup or becomes relevant to debugging.
 - Do not actively monitor completion unless explicitly requested.
 - If monitoring is requested, allow long runtime windows (15-30+ minutes) and continue until completion unless operator instructs otherwise.
 - Report command errors immediately.