收口前端平台组件能力

新增 PlatformAsyncStatePanel 统一 profile 异步状态骨架
扩展 PlatformSegmentedTabs 支持滚动 tab 并接入创作入口与发现页
统一 PixelCloseButton 复用 PlatformModalCloseButton 像素关闭能力
抽取平台入口泥点前置提示弹层并收紧阻断语义
补充组件收口文档与共享决策记录

src/components/common/PlatformModalCloseButton.test.tsx

@@ -1,7 +1,8 @@
 /* @vitest-environment jsdom */
 
 import { render, screen } from '@testing-library/react';
-import { expect, test } from 'vitest';
+import userEvent from '@testing-library/user-event';
+import { expect, test, vi } from 'vitest';
 
 import { PlatformModalCloseButton } from './PlatformModalCloseButton';
 
@@ -80,9 +81,37 @@ test('supports pixel close button', () => {
 
   const button = screen.getByRole('button', { name: '关闭像素弹窗' });
 
-  expect(button.className).toContain('bg-black/20');
+  expect(button.className).toContain('bg-black/30');
   expect(button.className).toContain('text-zinc-400');
+  expect(button.className).toContain('absolute');
   expect(button.className).toContain('disabled:opacity-45');
+  expect(button.getAttribute('title')).toBe('关闭像素弹窗');
+});
+
+test('supports inline pixel placement and intercepted click behavior', async () => {
+  const user = userEvent.setup();
+  const onClick = vi.fn();
+  const onHeaderClick = vi.fn();
+
+  render(
+    <div onClick={onHeaderClick}>
+      <PlatformModalCloseButton
+        label="关闭像素标题栏"
+        variant="pixel"
+        placement="inline"
+        stopPropagation
+        onClick={onClick}
+      />
+    </div>,
+  );
+
+  const button = screen.getByRole('button', { name: '关闭像素标题栏' });
+  await user.click(button);
+
+  expect(button.className).toContain('relative');
+  expect(button.className).toContain('shrink-0');
+  expect(onClick).toHaveBeenCalledTimes(1);
+  expect(onHeaderClick).not.toHaveBeenCalled();
 });
 
 test('supports editor dark close button', () => {