调整图片画布路由和画布数据模型

将图片画布入口改为 /editor/canvas

新增 editor_canvas 表并关联 editor_project 默认画布

更新 project API 响应中的 canvas 快照兼容层

统一图片画布侧栏列表项和图标按钮组件

同步前端测试、SpacetimeDB bindings、技术文档和 TRACKING 记录

src/routing/appPageRoutes.test.ts

@@ -22,9 +22,13 @@ describe('appPageRoutes', () => {
   });
 
   it('resolves the image editor route', () => {
-    expect(resolveSelectionStageFromPath('/editor')).toBe('image-editor');
-    expect(resolveSelectionStageFromPath('/EDITOR/')).toBe('image-editor');
-    expect(resolvePathForSelectionStage('image-editor')).toBe('/editor');
+    expect(resolveSelectionStageFromPath('/editor/canvas')).toBe(
+      'image-editor',
+    );
+    expect(resolveSelectionStageFromPath('/EDITOR/CANVAS/')).toBe(
+      'image-editor',
+    );
+    expect(resolvePathForSelectionStage('image-editor')).toBe('/editor/canvas');
   });
 
   it('resolves jump-hop creation, gallery and runtime routes', () => {