feat(ui): Expose cache status and controls in UI

src/app_controller.py

@@ -1983,6 +1983,11 @@ class AppController:
   self.ui_base_system_prompt = ai_client._SYSTEM_PROMPT
   self.ui_use_default_base_prompt = False
 
+ def _cb_clear_summary_cache(self, user_data=None) -> None:
+  from src import summarize
+  summarize._summary_cache.clear()
+  self._push_mma_state_update()
+
  def _cb_show_base_prompt_diff(self, user_data=None) -> None:
   self._show_base_prompt_diff_modal = True