完善项目导入、模板与分割工作区交互

- 增强 DICOM/视频项目导入与演示数据：DICOM 按文件名自然顺序处理，导入后展示上传与解析任务进度，恢复演示出厂设置保留演示视频和演示 DICOM 项目，并补充 demo media seed 逻辑。

- 完善项目管理：项目支持重命名、删除、复制，删除使用站内确认弹窗，复制支持新项目重置和全内容复制，DICOM 项目不显示生成帧入口。

- 完善 GT Mask 与导出链路：只支持 8-bit maskid 图导入，非法/全背景图明确拒绝，尺寸自动适配，高精度 polygon 回显；统一导出默认当前帧，GT_label 使用 uint8 和真实 maskid，待分类 maskid 0 与背景一致。

- 完善分割工作区交互：新增画笔和橡皮擦并支持尺寸控制，移除创建点/线段入口，工具栏按类别分隔，AI 智能分割使用明确 AI 图标，取消黄色 seed point，清空/删除传播 mask 后同步清理空帧时间轴状态。

- 完善传播与时间轴：自动传播使用 SAM 2.1 权重任务，参考帧无遮罩时提示，传播历史按同一蓝色系递进变暗，删除/清空传播链时保留人工或独立 AI 标注来源。

- 完善模板库：新增头颈部 CT 分割默认模板，所有模板保留 maskid 0 待分类，支持鼠标复制模板、拖拽层级、JSON 批量导入预览、删除 label 和站内删除确认。

- 完善用户与高风险确认：用户改密码、删除用户、恢复演示出厂设置和清空人工/AI 标注帧均改为站内确认交互，避免浏览器原生 prompt/confirm。

- 补充前后端测试与文档：更新项目、模板、GT 导入、导出、传播、DICOM、用户管理等测试，并同步 README、AGENTS 和 doc 下实现/契约/测试计划文档。

src/components/CanvasArea.test.tsx

@@ -466,7 +466,7 @@ describe('CanvasArea', () => {
     expect(screen.getByText('当前图层: 胆囊 #21')).toBeInTheDocument();
   });
 
-  it('renders imported GT seed points for editable point regions', () => {
+  it('does not render stored GT seed points as visible editable handles', () => {
     useStore.setState({
       masks: [
         {
@@ -482,7 +482,28 @@ describe('CanvasArea', () => {
 
     render(<CanvasArea activeTool="move" frame={frame} />);
 
-    expect(screen.getAllByTestId('konva-circle')).toHaveLength(2);
+    expect(screen.queryAllByTestId('konva-circle')
+      .filter((element) => element.getAttribute('data-fill') === '#facc15')).toHaveLength(0);
+  });
+
+  it('does not derive visible seed points for ordinary polygon masks', () => {
+    useStore.setState({
+      masks: [
+        {
+          id: 'manual-1',
+          frameId: 'frame-1',
+          pathData: 'M 10 10 L 90 10 L 90 40 Z',
+          label: 'Manual',
+          color: '#06b6d4',
+          segmentation: [[10, 10, 90, 10, 90, 40]],
+        },
+      ],
+    });
+
+    render(<CanvasArea activeTool="move" frame={frame} />);
+
+    expect(screen.queryAllByTestId('konva-circle')
+      .filter((element) => element.getAttribute('data-fill') === '#facc15')).toHaveLength(0);
   });
 
   it('selects a polygon mask and drags a vertex into dirty saved state', () => {
@@ -668,6 +689,79 @@ describe('CanvasArea', () => {
     expect(onDeleteMaskAnnotations).toHaveBeenCalledWith(['99']);
   });
 
+  it('deletes linked propagated masks while keeping independent AI inference masks', () => {
+    const onDeleteMaskAnnotations = vi.fn();
+    const propagatedFrame = { ...frame, id: 'frame-2', index: 1, url: '/frame-2.jpg' };
+    useStore.setState({
+      masks: [
+        {
+          id: 'annotation-99',
+          annotationId: '99',
+          frameId: 'frame-1',
+          pathData: 'M 10 10 L 90 10 L 90 40 Z',
+          label: 'Seed',
+          color: '#06b6d4',
+          saveStatus: 'saved',
+          saved: true,
+          segmentation: [[10, 10, 90, 10, 90, 40]],
+        },
+        {
+          id: 'annotation-100',
+          annotationId: '100',
+          frameId: 'frame-2',
+          pathData: 'M 12 10 L 92 10 L 92 40 Z',
+          label: 'Propagated A',
+          color: '#06b6d4',
+          saveStatus: 'saved',
+          saved: true,
+          segmentation: [[12, 10, 92, 10, 92, 40]],
+          metadata: {
+            source: 'sam2.1_hiera_tiny_propagation',
+            source_annotation_id: 99,
+            source_mask_id: 'annotation-99',
+            propagation_seed_key: 'annotation:99',
+          },
+        },
+        {
+          id: 'annotation-101',
+          annotationId: '101',
+          frameId: 'frame-3',
+          pathData: 'M 14 10 L 94 10 L 94 40 Z',
+          label: 'Propagated B',
+          color: '#06b6d4',
+          saveStatus: 'saved',
+          saved: true,
+          segmentation: [[14, 10, 94, 10, 94, 40]],
+          metadata: {
+            source: 'sam2.1_hiera_tiny_propagation',
+            source_annotation_id: 99,
+            source_mask_id: 'annotation-99',
+            propagation_seed_key: 'annotation:99',
+          },
+        },
+        {
+          id: 'annotation-102',
+          annotationId: '102',
+          frameId: 'frame-3',
+          pathData: 'M 200 10 L 260 10 L 260 40 Z',
+          label: 'AI Candidate',
+          color: '#22c55e',
+          saveStatus: 'saved',
+          saved: true,
+          segmentation: [[200, 10, 260, 10, 260, 40]],
+          metadata: { source: 'ai_segmentation' },
+        },
+      ],
+    });
+
+    render(<CanvasArea activeTool="move" frame={propagatedFrame} onDeleteMaskAnnotations={onDeleteMaskAnnotations} />);
+    fireEvent.click(screen.getByTestId('konva-path'));
+    fireEvent.keyDown(window, { key: 'Delete' });
+
+    expect(useStore.getState().masks.map((mask) => mask.id)).toEqual(['annotation-99', 'annotation-102']);
+    expect(onDeleteMaskAnnotations).toHaveBeenCalledWith(['100', '101']);
+  });
+
   it('inserts a polygon vertex from an edge midpoint handle', () => {
     useStore.setState({
       masks: [
@@ -784,7 +878,8 @@ describe('CanvasArea', () => {
     const paths = screen.getAllByTestId('konva-path');
     fireEvent.click(paths[0]);
     expect(screen.getByText('已选 1')).toBeInTheDocument();
-    expect(screen.queryAllByTestId('konva-circle')).toHaveLength(0);
+    expect(screen.queryAllByTestId('konva-circle')
+      .filter((element) => element.getAttribute('data-fill') === '#ffffff')).toHaveLength(0);
     fireEvent.click(paths[1]);
     expect(screen.getByText('已选 2')).toBeInTheDocument();
     fireEvent.click(screen.getByRole('button', { name: '合并选中' }));
@@ -1069,7 +1164,8 @@ describe('CanvasArea', () => {
         shape: '多边形',
       }),
     }));
-    expect(screen.queryAllByTestId('konva-circle')).toHaveLength(0);
+    expect(screen.queryAllByTestId('konva-circle')
+      .filter((element) => element.getAttribute('data-fill') === '#facc15')).toHaveLength(0);
   });
 
   it('shows contextual guidance for boolean selection ordering', () => {