refactor: remove models snapshot feature and related code

- Remove models snapshot UI section from Models page
- Delete models API route handler and related logic
- Remove models store implementation and exports
- Clean up internationalization messages for removed feature
- Update main entry point exports to exclude models store

electron/api/router.ts

@@ -11,7 +11,6 @@ import { handleCronRoutes } from './routes/cron';
 import { handleFileRoutes } from './routes/files';
 import { handleGatewayRoutes } from './routes/gateway';
 import { handleKnowledgeRoutes } from './routes/knowledge';
-import { handleModelRoutes } from './routes/models';
 import { handleProviderRoutes } from './routes/providers';
 import { handleSessionRoutes } from './routes/sessions';
 import { handleSkillRoutes } from './routes/skills';
@@ -25,7 +24,6 @@ const routeHandlers: RouteHandler[] = [
   handleProviderRoutes,
   handleChannelRoutes,
   handleAgentRoutes,
-  handleModelRoutes,
   handleCronRoutes,
   handleGatewayRoutes,
   handleKnowledgeRoutes,