fix(@vben-core/form-ui): restore lock screen form submission (#8195)

* fix(@vben-core/form-ui): avoid stale form context access

* fix(@vben/playground): constrain date range codec fields

* test(@vben-core/form-ui): harden benchmark fixtures

* docs(@vben/docs): document form runtime and benchmarks

* fix(@vben/docs): 明确 getValues/submit 返回值及 submit 参数类型

packages/@core/ui-kit/form-ui/src/form-api.ts

@@ -404,6 +404,11 @@ export class FormApi<
     }
   }
 
+  async setFieldError(fieldName: FormFieldName<TFormValues>, error?: string) {
+    const form = await this.getForm();
+    form.setFieldError(fieldName, error);
+  }
+
   async setFieldValue<TFieldName extends FormFieldName<TFormValues>>(
     field: TFieldName,
     value: FormFieldValue<TFormValues, NoInfer<TFieldName>>,