Move UI code from assistant_context_editor -> agent_ui (#33289)
This breaks a transitive dependency of `agent` on UI crates. I've also
found and eliminated some dead code in assistant_context_editor.
Release Notes:
- N/A
4cd4d28531Max Brunsfeld committed on 6/24/2025, 5:22:01 AM· committed by GitHubparent786e724