chore: pin GitHub Actions to full-length commit SHAs - #31

Bugbot Analysis Progress (1m 44s elapsed)

✅ Gathered PR context (4s)
✅ Completed bug detection (1m 40s)
✅ Posted analysis results (1s)

Final Result: Bugbot completed review - no issues found! ✅

Request ID: serverGenReqId_c04f46fe-9fd0-4394-8a94-80973394bc7c