fix(server): restore PR detection without HOME - #4985

Bugbot Analysis Progress (7m 58s elapsed)

✅ Gathered PR context (8s)
✅ Completed bug detection (7m 49s)
✅ Posted analysis results (1s)

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

Request ID: serverGenReqId_88c2b67d-aa7e-46f6-8391-00178d2e0fe8