chore: update GitHub stars workflow schedule

- Change schedule from daily to weekly (Monday at midnight UTC)
- Update PR description to reflect weekly update frequency
- Reduce API usage and workflow runs

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: ericyangpan

.github/workflows/update-github-stars.yml

@@ -2,8 +2,8 @@ name: Update GitHub Stars
 
 on:
   schedule:
-    # Run daily at midnight UTC
-    - cron: '0 0 * * *'
+    # Run weekly on Monday at midnight UTC
+    - cron: '0 0 * * 1'
   workflow_dispatch:
     # Allow manual triggering
 
@@ -52,7 +52,7 @@ jobs:
           title: 'chore: update GitHub stars data'
           body: |
             ## Summary
-            Automated daily update of GitHub stars data.
+            Automated weekly update of GitHub stars data.
 
             ### Changes
             - Updated `manifests/github-stars.json` with latest star counts