fix(gui): prevent dictionary size change during iteration

- Wrap discussions.items() with list() in takes_panel to prevent
  RuntimeError when dictionary changes during iteration
- This was causing crashes when switching discussions

src/app_controller.py

@@ -1544,7 +1544,6 @@ class AppController:
    self.active_project_path = fallback_path
    if fallback_path not in self.project_paths:
     self.project_paths.append(fallback_path)
-  self._refresh_from_project()
   self._configure_mcp_for_project()
 
  def _prune_old_logs(self) -> None: