action_focus_previous

Step checkbox focus backward for the app's shift+tab router.

The app-level priority shift+tab -> toggle_auto_approve binding wins dispatch, and action_toggle_auto_approve routes cursor-style modals to action_move_up via _SupportsReverseNav. With settings expanded that would only move the row cursor and strand focus on the first checkbox, so the app branches here instead (see DeepAgentsApp.action_toggle_auto_approve).