实现游戏共创 M3：创作族谱树与衍生列表

- 新增 module-game-distribution/src/lineage.rs：锚点可读性、可见性过滤、稳定排序、上限截断的纯函数，附 15 个单测（复用 M1 的软删除判定，不重写第二套规则）
- 新增公开只读 procedure get_game_distribution_lineage / list_game_distribution_derived_games；锚点必须公开可读（未公开/已软删除/不存在一律按不存在处理），树内只出现未软删除且已公开的节点，不补 null 占位节点
- api-server 新增 GET /games/{id}/lineage 与 /games/{id}/derived（匿名可读、no-store），响应走结构化 DTO，节点键集合由测试钉死，杜绝下发对象键/素材键
- 作者自有游戏聚合追加 forkCount（与公开详情 forkCount 同口径），供「被改编 N」入口使用
- shared-contracts 与 TS 契约新增 LineageNode / LineageResponse / DerivedResponse 三型并登记 DTO 一致性检查
- 前端新增 /games/lineage 族谱页，登记 stage 类型、路由表、页面标题与壳层渲染分支；详情页共创卡新增「查看创作族谱」入口（仅已公开作品）
- 我的作品页新增「被改编 N」行内展开，列出直接子代的标题/作者/代际/状态，含空态与失败重试（仅已公开作品）
- 补前端组件/路由/标题/客户端用例与 api-server 路由、负载映射用例；同步里程碑验收标准与技术方案 §3.4 的锚点可读性口径

src/components/platform-entry/PlatformEntryActiveFlowShell.test.tsx

@@ -49,7 +49,9 @@ const gameDistributionMock = vi.hoisted(() => ({
   createGame: vi.fn(),
   createGameVersion: vi.fn(),
   deleteMyGame: vi.fn(),
+  getDerivedGames: vi.fn(),
   getGame: vi.fn(),
+  getGameLineage: vi.fn(),
   getGameVersion: vi.fn(),
   getMyGame: vi.fn(),
   listGames: vi.fn(),
@@ -1172,3 +1174,116 @@ describe('作品管理 owner 作用域', () => {
     expect(gameDistributionMock.getMyGame).not.toHaveBeenCalled();
   });
 });
+
+describe('创作族谱', () => {
+  const lineageTree = {
+    rootGameId: 'game-root',
+    root: {
+      gameId: 'game-root',
+      title: '母版',
+      authorName: '原作者',
+      generation: 0,
+      parentGameId: null,
+      playCount: 3,
+      status: 'published',
+    },
+    nodes: [
+      {
+        gameId: 'game-root',
+        title: '母版',
+        authorName: '原作者',
+        generation: 0,
+        parentGameId: null,
+        playCount: 3,
+        status: 'published',
+      },
+      {
+        gameId: 'game-leaf',
+        title: '叶节点',
+        authorName: '改编者',
+        generation: 1,
+        parentGameId: 'game-root',
+        playCount: 1,
+        status: 'published',
+      },
+    ],
+    truncated: false,
+  };
+
+  it('族谱页按根作品渲染树，未登录也能浏览并跳转节点', async () => {
+    window.history.replaceState(
+      null,
+      '',
+      '/games/lineage?id=game-root&from=game-leaf',
+    );
+    gameDistributionMock.getGameLineage.mockResolvedValue(lineageTree);
+    const setSelectionStage = vi.fn();
+
+    render(
+      <PlatformEntryFlowShellImpl
+        selectionStage="game-lineage"
+        setSelectionStage={setSelectionStage}
+      />,
+    );
+
+    expect(await screen.findByText('叶节点')).toBeTruthy();
+    expect(gameDistributionMock.getGameLineage).toHaveBeenCalledWith(
+      'game-root',
+    );
+    fireEvent.click(screen.getByRole('button', { name: '母版' }));
+    expect(setSelectionStage).toHaveBeenCalledWith('game-detail', {
+      path: '/games/detail?id=game-root',
+    });
+  });
+
+  it('详情页的族谱入口带上根作品与当前作品', async () => {
+    window.history.replaceState(null, '', '/games/detail?id=game-1');
+    gameDistributionMock.getGame.mockResolvedValue({
+      id: 'game-1',
+      title: '衍生作品',
+      summary: '已发布',
+      description: '',
+      category: '动作',
+      tags: [],
+      coverColor: '#d77a51',
+      icon: '✦',
+      author: { id: 'author-1', name: '测试作者' },
+      deviceSupport: { desktop: true, mobile: true, touch: true },
+      status: 'published',
+      currentVersion: {
+        id: 'version-1',
+        version: '1.0.0',
+        entryUrl: 'https://play.example.test/releases/version-1/index.html',
+        sha256: 'sha256',
+        publishedAt: '2026-09-18T00:00:00.000Z',
+        controls: ['键盘'],
+      },
+      playCount: 1,
+      createdAt: '2026-09-18T00:00:00.000Z',
+      forkCount: 0,
+      lineage: {
+        generation: 1,
+        rootGameId: 'game-root',
+        rootTitle: '母版',
+        parentGameId: 'game-root',
+        parentTitle: '母版',
+        parentAuthorName: '原作者',
+      },
+    });
+    const setSelectionStage = vi.fn();
+
+    render(
+      <PlatformEntryFlowShellImpl
+        selectionStage="game-detail"
+        setSelectionStage={setSelectionStage}
+      />,
+    );
+
+    fireEvent.click(
+      await screen.findByRole('button', { name: '查看创作族谱' }),
+    );
+    expect(setSelectionStage).toHaveBeenCalledWith('game-lineage', {
+      path: '/games/lineage?id=game-root&from=game-1',
+    });
+  });
+});