feat(rag): Implement RAG engine, configuration schema, and vector store integration

src/app_controller.py

@@ -201,6 +201,7 @@ class AppController:
   self._pending_actions: Dict[str, ConfirmDialog] = {}
   self._pending_ask_dialog: bool = False
   self.mcp_config: models.MCPConfiguration = models.MCPConfiguration()
+  self.rag_config: Optional[models.RAGConfig] = None
   # AI settings state
   self._current_provider: str = "gemini"
   self._current_model: str = "gemini-2.5-flash-lite"
@@ -948,6 +949,12 @@ class AppController:
   else:
    self.mcp_config = models.MCPConfiguration()
 
+  rag_data = self.config.get('rag')
+  if rag_data:
+   self.rag_config = models.RAGConfig.from_dict(rag_data)
+  else:
+   self.rag_config = models.RAGConfig()
+
   from src.personas import PersonaManager
   self.persona_manager = PersonaManager(Path(self.active_project_path).parent if self.active_project_path else None)
   self.personas = self.persona_manager.load_all()
@@ -2526,6 +2533,10 @@ class AppController:
   self.config["ai"]["system_prompt"] = self.ui_global_system_prompt
   self.config["ai"]["base_system_prompt"] = self.ui_base_system_prompt
   self.config["ai"]["use_default_base_prompt"] = self.ui_use_default_base_prompt
+  
+  if self.rag_config:
+   self.config["rag"] = self.rag_config.to_dict()
+   
   self.config["projects"] = {"paths": self.project_paths, "active": self.active_project_path}
   from src import bg_shader
   # Update gui section while preserving other keys like bg_shader_enabled