Fix broker shim to use proper MetadataService API

The broker shim was incorrectly accessing the private `.registry` property of MetadataManager using `(metadataService as any).registry.keys()`. This is an internal implementation detail that should not be accessed directly.

Fixed to use the proper `getRegisteredTypes()` method from the IMetadataService interface, which is the correct way to query all registered metadata types.

Also added missing Wrench icon registration for tools in the AI protocol plugin's activate() method.

Agent-Logs-Url: https://github.com/objectstack-ai/framework/sessions/d86787db-36e6-48fa-88cf-ff327fa67b0c

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Claude

apps/studio/src/lib/create-broker-shim.ts

@@ -185,11 +185,10 @@ export function createBrokerShim(kernel: any): BrokerShim {
                     // Combine types from both SchemaRegistry (static) and MetadataService (runtime)
                     const schemaTypes = SchemaRegistry.getRegisteredTypes();
 
-                    // MetadataService exposes types through its internal registry
-                    // Access via the manager's registry property if available
+                    // MetadataService exposes types through getRegisteredTypes() method
                     let runtimeTypes: string[] = [];
-                    if (metadataService && (metadataService as any).registry) {
-                        runtimeTypes = Array.from((metadataService as any).registry.keys());
+                    if (metadataService && typeof metadataService.getRegisteredTypes === 'function') {
+                        runtimeTypes = await metadataService.getRegisteredTypes();
                     }
 
                     // Merge and deduplicate

apps/studio/src/plugins/built-in/ai-plugin.tsx

@@ -9,7 +9,7 @@
 
 import { defineStudioPlugin } from '@objectstack/spec/studio';
 import type { StudioPlugin } from '../types';
-import { Bot, BookOpen } from 'lucide-react';
+import { Bot, BookOpen, Wrench } from 'lucide-react';
 
 export const aiProtocolPlugin: StudioPlugin = {
   manifest: defineStudioPlugin({
@@ -37,6 +37,7 @@ export const aiProtocolPlugin: StudioPlugin = {
 
   activate(api) {
     api.registerMetadataIcon('agent', Bot, 'Agents');
+    api.registerMetadataIcon('tool', Wrench, 'Tools');
     api.registerMetadataIcon('ragPipeline', BookOpen, 'RAG Pipelines');
   },
 };