收口前端平台组件库能力

新增 PlatformUiKit 通用弹窗、按钮、状态、空态、媒体、表单和标签等公共组件
迁移结果页、创作工作台、认证入口、RPG 暗色面板和运行态弹窗的重复 UI chrome
补充组件测试、页面回归测试、技术文档和 Hermes 共享决策记录

src/components/common/CopyFeedbackMessage.test.tsx

@@ -0,0 +1,39 @@
+/* @vitest-environment jsdom */
+
+import { render, screen } from '@testing-library/react';
+import { expect, test } from 'vitest';
+
+import { CopyFeedbackMessage } from './CopyFeedbackMessage';
+
+test('renders nothing while copy feedback is idle', () => {
+  const { container } = render(
+    <CopyFeedbackMessage state="idle" className="copy-toast" />,
+  );
+
+  expect(container.textContent).toBe('');
+});
+
+test('renders copied and failed feedback labels', () => {
+  const { rerender } = render(
+    <CopyFeedbackMessage
+      state="copied"
+      copiedLabel="分享内容已复制"
+      failedLabel="分享失败"
+      className="copy-toast"
+    />,
+  );
+
+  const copied = screen.getByText('分享内容已复制');
+  expect(copied.className).toContain('copy-toast');
+
+  rerender(
+    <CopyFeedbackMessage
+      state="failed"
+      copiedLabel="分享内容已复制"
+      failedLabel="分享失败"
+      className="copy-toast"
+    />,
+  );
+
+  expect(screen.getByText('分享失败')).toBeTruthy();
+});