[F1] @vue-flow/core 依赖 + DagCanvas 基础组件

- apps/web-antd/src/components/iot-dag/ 7 文件
  - DagCanvas.vue / DagCanvasToolbar.vue
  - hooks/useDagState.ts（50 步撤销栈 + structuredClone 深拷贝）
  - hooks/useDagShortcuts.ts（Del/Ctrl+Z/Ctrl+Y + input guard）
  - types.ts（DagNode/DagEdge/DagCanvasProps + 6 emits）
  - index.ts barrel + __tests__/DagCanvas.spec.ts（16 用例全绿）
- pnpm-workspace.yaml: catalog 新增 @vue-flow/{core,background,controls,minimap}
- apps/web-antd/package.json: 4 包全部 'catalog:' 引用
- i18n: zh-CN/en-US iot.dag.toolbar.* + iot.dag.canvas.* 同步
- Known Pitfalls 落地: ⚠️ catalog 约束 / 样式 import / TS 严格零 any

note: Acceptance #7 (Storybook/playground) 项目未集成 Storybook,
      由 F7 规则链编辑页自然 dogfood。

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web-antd/src/locales/langs/en-US/page.json

@@ -39,5 +39,21 @@
       "video": "Video",
       "voice": "Voice"
     }
+  },
+  "iot": {
+    "dag": {
+      "toolbar": {
+        "zoomIn": "Zoom In",
+        "zoomOut": "Zoom Out",
+        "fitView": "Fit View",
+        "undo": "Undo (Ctrl+Z)",
+        "redo": "Redo (Ctrl+Y)",
+        "save": "Save"
+      },
+      "canvas": {
+        "readonly": "Read-only mode",
+        "empty": "Drag nodes to canvas to start"
+      }
+    }
   }
 }

apps/web-antd/src/locales/langs/zh-CN/page.json

@@ -39,5 +39,21 @@
       "video": "视频",
       "voice": "语音"
     }
+  },
+  "iot": {
+    "dag": {
+      "toolbar": {
+        "zoomIn": "放大",
+        "zoomOut": "缩小",
+        "fitView": "适应视图",
+        "undo": "撤销 (Ctrl+Z)",
+        "redo": "重做 (Ctrl+Y)",
+        "save": "保存"
+      },
+      "canvas": {
+        "readonly": "只读模式",
+        "empty": "拖拽节点到画布开始编排"
+      }
+    }
   }
 }