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/run-learnings.md

@@ -183,3 +183,12 @@ This file stores run-specific examples only when a run produced a new learning r
   - After `cmc-templates.py`, verify both the generated `.ts` files and the controller config `specPattern` before launching `run-sorry-cypress.py`.
   - Prefer direct controller-side inspection of the config block and file presence rather than fragile shell-escaped regex checks.
   - If the requested VM list is not visibly present in both places, stop and report the mismatch instead of starting the runner.
+
+## Run Learning: 2026-03-26 (Do not repeat harmless reset-failed watcher noise)
+- Observed requirement:
+  - `systemctl reset-failed atvm-run-watcher@...` often reports that the unit was not loaded.
+  - In normal watcher startup this has been harmless and does not change the run outcome.
+  - Repeating that note in routine run confirmations adds noise without helping the operator.
+- Action for future runs:
+  - Do not mention expected, harmless `reset-failed` output in routine run updates.
+  - Only mention it if it actually prevents watcher startup or becomes relevant to debugging.