fix(server,web): show Claude thinking blocks in thread timelines - #6429

Bugbot Analysis Progress (7m 38s elapsed)

✅ Gathered PR context (13s)
✅ Completed bug detection (7m 25s)
✅ Posted analysis results (1s)

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

Request ID: serverGenReqId_9cbb7a8f-8817-4b12-a859-e6cb4c9aa407