fix(web): stop wrapping partial code block selections in markdown fences - #5069

Bugbot Analysis Progress (5m 42s elapsed)

✅ Gathered PR context (10s)
✅ Completed bug detection (5m 31s)
✅ Posted analysis results (1s)

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

Request ID: serverGenReqId_f771e301-f1dc-47b5-99b1-2c7ac2780d0a