fix: decouple data tool registration from metadataService and update stale JSDoc

- plugin.ts: Register data tools whenever dataEngine is available, not
  gated on metadataService. Agent auto-registration still requires
  metadataService and is nested inside a separate check.
- data-tools.ts: Update JSDoc/example to match new DataToolContext
  (no longer references metadataService).

Agent-Logs-Url: https://github.com/objectstack-ai/framework/sessions/f69965e4-42f5-4f19-84ef-74c854bdf5ac

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

Author: Copilot

packages/services/service-ai/src/plugin.ts

@@ -254,24 +254,26 @@ export class AIServicePlugin implements Plugin {
       ctx.logger.debug('[AI] Metadata service not available');
     }
 
-    // Data tools require both data engine and metadata service
+    // Data tools require only the data engine
     try {
       const dataEngine = ctx.getService<IDataEngine>('data');
-      if (dataEngine && metadataService) {
+      if (dataEngine) {
         registerDataTools(this.service.toolRegistry, { dataEngine });
         ctx.logger.info('[AI] Built-in data tools registered');
 
-        // Register the built-in data_chat agent only if it does not already exist
-        const agentExists =
-          typeof metadataService.exists === 'function'
-            ? await metadataService.exists('agent', DATA_CHAT_AGENT.name)
-            : false;
-
-        if (!agentExists) {
-          await metadataService.register('agent', DATA_CHAT_AGENT.name, DATA_CHAT_AGENT);
-          ctx.logger.info('[AI] data_chat agent registered');
-        } else {
-          ctx.logger.debug('[AI] data_chat agent already exists, skipping auto-registration');
+        // Register the built-in data_chat agent (requires metadata service)
+        if (metadataService) {
+          const agentExists =
+            typeof metadataService.exists === 'function'
+              ? await metadataService.exists('agent', DATA_CHAT_AGENT.name)
+              : false;
+
+          if (!agentExists) {
+            await metadataService.register('agent', DATA_CHAT_AGENT.name, DATA_CHAT_AGENT);
+            ctx.logger.info('[AI] data_chat agent registered');
+          } else {
+            ctx.logger.debug('[AI] data_chat agent already exists, skipping auto-registration');
+          }
         }
       }
     } catch {

packages/services/service-ai/src/tools/data-tools.ts

@@ -273,15 +273,13 @@ function createAggregateDataHandler(ctx: DataToolContext): ToolHandler {
 /**
  * Register all built-in data tools on the given {@link ToolRegistry}.
  *
- * Typically called from the `ai:ready` hook after both the data engine
- * and metadata service are available.
+ * Typically called from the `ai:ready` hook after the data engine is available.
  *
  * @example
  * ```ts
  * ctx.hook('ai:ready', async (aiService) => {
  *   const dataEngine = ctx.getService<IDataEngine>('data');
- *   const metadataService = ctx.getService<IMetadataService>('metadata');
- *   registerDataTools(aiService.toolRegistry, { dataEngine, metadataService });
+ *   registerDataTools(aiService.toolRegistry, { dataEngine });
  * });
  * ```
  */