chore(workflows): extend expires to 3d, add auto-merge for doc updater

- Increase safe-output expiration from 1d to 3d across all gh-aw workflows
- Add auto-merge: true to daily-doc-updater safe-output PR config
- Maintenance schedule auto-adjusted from every 2h to every 12h

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: hkirschner_microsoft

.github/workflows/agentics-maintenance.yml

@@ -34,7 +34,7 @@ name: Agentic Maintenance
 
 on:
   schedule:
-    - cron: "37 */2 * * *"  # Every 2 hours (based on minimum expires: 1 days)
+    - cron: "37 */12 * * *"  # Every 12 hours (based on minimum expires: 3 days)
   workflow_dispatch:
     inputs:
       operation:

.github/workflows/ci-doctor.lock.yml

@@ -27,7 +27,7 @@ strict: true
 
 safe-outputs:
   create-issue:
-    expires: 1d
+    expires: 3d
     title-prefix: "[CI Failure Doctor] "
     labels: [ci-failure, automation]
     close-older-issues: true