feat(plugin): support enterprise extension (#861)

electron/extensions/builtin/index.ts

@@ -0,0 +1,8 @@
+import { registerBuiltinExtension } from '../loader';
+import { createClawHubMarketplaceExtension } from './clawhub-marketplace';
+import { createDiagnosticsExtension } from './diagnostics';
+
+export function registerAllBuiltinExtensions(): void {
+  registerBuiltinExtension('builtin/clawhub-marketplace', createClawHubMarketplaceExtension);
+  registerBuiltinExtension('builtin/diagnostics', createDiagnosticsExtension);
+}