收口创作代理输入错误提示

将 creation-agent composer 错误条迁移到 PlatformStatusMessage platform surface

补充错误条公共状态样式断言

更新 PlatformUiKit 文档和 Hermes 决策记录

src/components/creation-agent/CreationAgentWorkspace.test.tsx

@@ -721,8 +721,14 @@ test('creation agent workspace shows document parse error near composer', async
   });
 
   await waitFor(() => {
-    expect(
-      screen.getByText('暂时只支持 txt、md、csv、json 文本文档。'),
-    ).toBeTruthy();
+    const errorMessage = screen.getByText(
+      '暂时只支持 txt、md、csv、json 文本文档。',
+    );
+
+    expect(errorMessage).toBeTruthy();
+    expect(errorMessage.className).toContain('platform-status-message');
+    expect(errorMessage.className).toContain(
+      'bg-[var(--platform-button-danger-fill)]',
+    );
   });
 });

src/components/creation-agent/CreationAgentWorkspace.tsx

@@ -623,7 +623,8 @@ export function CreationAgentWorkspace({
           {documentInputError || referenceImageError || error ? (
             <PlatformStatusMessage
               tone="error"
-              className="mx-4 mb-3 rounded-[1rem] border-red-200/70 text-red-600"
+              surface="platform"
+              className="mx-4 mb-3 rounded-[1rem]"
             >
               {documentInputError || referenceImageError || error}
             </PlatformStatusMessage>