Fix subagent session restore takeover - #4543

Bugbot Analysis Progress (20m 48s elapsed)

✅ Gathered PR context (4s)
✅ Completed bug detection (20m 44s)
✅ Posted analysis results (1s)

Final Result: Bugbot completed review - no issues found. 1 previously reported issue remain unresolved.

Request ID: serverGenReqId_cc7fa0be-ec32-499d-8583-1b6cb1ab3fd2