fix(phase6): resolve minimax regression and context snapshotting crash

src/app_controller.py

@@ -371,8 +371,7 @@ class AppController:
    'gcli_path': 'ui_gemini_cli_path',
    'output_dir': 'ui_output_dir',
    'files_base_dir': 'ui_files_base_dir',
-   'files': 'files',
-   'screenshots': 'screenshots',
+   'files': 'ui_file_paths',   'screenshots': 'screenshots',
    'ai_status': 'ai_status',
    'ai_response': 'ai_response',
    'active_discussion': 'active_discussion',
@@ -2633,7 +2632,7 @@ class AppController:
   disc_data = discussions.setdefault(self.active_discussion, project_manager.default_discussion())
   disc_data["history"] = history_strings
   disc_data["last_updated"] = project_manager.now_ts()
-  disc_data["context_snapshot"] = [f.to_dict() for f in self.files]
+  disc_data["context_snapshot"] = [f.to_dict() if hasattr(f, "to_dict") else {"path": str(f)} for f in self.files]
 
  def _create_discussion(self, name: str) -> None:
   """