Session archive, delete, rename, and question reply block on API response #27911

Describe the bug

Session management operations (archive, delete, rename) and question replies await the API response before updating the UI, causing perceived latency:

• Archive/Delete: waits for the server response before removing the session from the sidebar and navigating away
• Rename: waits for the server response before updating the title in the sidebar
• Question reply/reject: uses mutateAsync and awaits, even though the dock is already dismissed by onMutate

Steps to reproduce

1. Open the web UI on a slow connection
2. Archive or delete a session
3. Observe the delay before the session disappears from the sidebar

Expected behavior

All operations should update the UI optimistically (immediately) and rollback on API error.

System info

• OpenCode version: v1.15.3
• OS: Linux