Update oncall sync workflow schedule and triggers

- Change schedule from midnight to 1AM UTC to allow rotation to take effect
- Add push trigger for main branch to sync on deployment
- Keep manual workflow_dispatch trigger

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: d-bytebase

.github/workflows/sync-oncall.yml

@@ -2,8 +2,11 @@ name: Sync Oncall to Google Group
 
 on:
   schedule:
-    # Run daily at 00:00 UTC
-    - cron: '0 0 * * *'
+    # Run daily at 01:00 UTC (rotation starts at 00:00 UTC)
+    - cron: '0 1 * * *'
+  push:
+    branches:
+      - main
   workflow_dispatch: # Allow manual trigger
 
 jobs: