fix(server): add missing searchRoles to Item model

Add searchRoles static property to enable searching items by name and code.
This fixes the 500 Internal Server Error when searching items via
/api/items?search_keyword=...

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

packages/server/src/modules/Items/models/Item.ts

@@ -70,6 +70,16 @@ export class Item extends TenantBaseModel {
     };
   }
 
+  /**
+   * Model search roles.
+   */
+  static get searchRoles() {
+    return [
+      { condition: 'or', fieldKey: 'name', comparator: 'contains' },
+      { condition: 'or', fieldKey: 'code', comparator: 'like' },
+    ];
+  }
+
   /**
    * Relationship mapping.
    */