refactor(mcp): call metadata services directly instead of REST layer (#16349)

## Summary

Refactors MCP metadata tools to call underlying services directly
instead of going through the REST layer. This makes MCP a pure
presentation layer.

### Changes

**Created:**
-
`packages/twenty-server/src/engine/metadata-modules/metadata-tools/metadata-tools.module.ts`
- Module that exports MetadataToolsFactory
-
`packages/twenty-server/src/engine/metadata-modules/metadata-tools/services/metadata-tools.factory.ts`
- Factory that generates 8 metadata tools using Zod schemas:
- `get-object-metadata`, `create-object-metadata`,
`update-object-metadata`, `delete-object-metadata`
- `get-field-metadata`, `create-field-metadata`,
`update-field-metadata`, `delete-field-metadata`

**Modified:**
-
`packages/twenty-server/src/engine/api/mcp/services/mcp-metadata.service.ts`
- Uses new factory instead of REST-based services
- `packages/twenty-server/src/engine/api/mcp/mcp.module.ts` - Imports
MetadataToolsModule, removes old service imports

**Deleted:**
-
`packages/twenty-server/src/engine/api/mcp/services/tools/create.tools.service.ts`
-
`packages/twenty-server/src/engine/api/mcp/services/tools/update.tools.service.ts`
-
`packages/twenty-server/src/engine/api/mcp/services/tools/delete.tools.service.ts`
-
`packages/twenty-server/src/engine/api/mcp/services/tools/get.tools.service.ts`
-
`packages/twenty-server/src/engine/api/mcp/services/tools/mcp-metadata-tools.service.ts`

### Architecture Improvement

**Before:**
```
MCP Tool → MetadataQueryBuilderFactory → RestApiService → GraphQL API → Service
```

**After:**
```
MCP Tool → Service (ObjectMetadataService / FieldMetadataService)
```

This follows the pattern established by `direct-record-tools.factory.ts`
and workflow tools.

packages/twenty-server/src/engine/metadata-modules/object-metadata/object-metadata.module.ts

@@ -25,6 +25,7 @@ import { ObjectMetadataGraphqlApiExceptionInterceptor } from 'src/engine/metadat
 import { ObjectMetadataEntity } from 'src/engine/metadata-modules/object-metadata/object-metadata.entity';
 import { ObjectMetadataResolver } from 'src/engine/metadata-modules/object-metadata/object-metadata.resolver';
 import { ObjectMetadataService } from 'src/engine/metadata-modules/object-metadata/object-metadata.service';
+import { ObjectMetadataToolsFactory } from 'src/engine/metadata-modules/object-metadata/tools/object-metadata-tools.factory';
 import { PermissionsModule } from 'src/engine/metadata-modules/permissions/permissions.module';
 import { PermissionsGraphqlApiExceptionFilter } from 'src/engine/metadata-modules/permissions/utils/permissions-graphql-api-exception.filter';
 import { RemoteTableRelationsModule } from 'src/engine/metadata-modules/remote-server/remote-table/remote-table-relations/remote-table-relations.module';
@@ -95,7 +96,11 @@ import { WorkspaceMigrationV2Module } from 'src/engine/workspace-manager/workspa
       ],
     }),
   ],
-  providers: [ObjectMetadataService, ObjectMetadataResolver],
-  exports: [ObjectMetadataService],
+  providers: [
+    ObjectMetadataService,
+    ObjectMetadataResolver,
+    ObjectMetadataToolsFactory,
+  ],
+  exports: [ObjectMetadataService, ObjectMetadataToolsFactory],
 })
 export class ObjectMetadataModule {}