The picker is built for saving, so it asks 'file exists — overwrite?' on
confirm. That's wrong when opening a script (you want an existing file). Add a
confirm_overwrite flag (default true; FileDialogState + OpenFileDialog param);
ConfirmFileDialog only prompts when it's set. The dashboard 'o' shortcut now
opens the dialog with confirm_overwrite=false. save/export keep the guard.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>