feat: frontend MVP — детальная схема связей устройств (AntV X6)

- React 18 + TypeScript strict + AntV X6 2.x + AntD 5 + Zustand
- Custom nodes: SiteNode, CrossDeviceNode, SpliceNode, DeviceNode, CardNode
- 8-слойный автолейаут, порты (left/right), линии с цветами по статусу
- Toolbar, дерево навигации, карточка объекта, таблица соединений
- Контекстные меню, легенда, drag линий/нод, создание линий из портов
- Моковые данные: 3 сайта, 10 устройств, 15 линий

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/package.json

@@ -0,0 +1,45 @@
+{
+  "name": "frontend",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc -b && vite build",
+    "lint": "eslint .",
+    "typecheck": "tsc -b --noEmit",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "@ant-design/icons": "^6.1.0",
+    "@antv/x6": "^2.19.2",
+    "@antv/x6-plugin-clipboard": "^2.1.6",
+    "@antv/x6-plugin-export": "^2.1.6",
+    "@antv/x6-plugin-history": "^2.2.4",
+    "@antv/x6-plugin-keyboard": "^2.2.3",
+    "@antv/x6-plugin-minimap": "^2.0.7",
+    "@antv/x6-plugin-selection": "^2.2.2",
+    "@antv/x6-plugin-snapline": "^2.1.7",
+    "@antv/x6-plugin-transform": "^2.1.8",
+    "@antv/x6-react-shape": "^2.2.3",
+    "antd": "^6.3.0",
+    "react": "^19.2.0",
+    "react-dom": "^19.2.0",
+    "xlsx": "^0.18.5",
+    "zustand": "^5.0.11"
+  },
+  "devDependencies": {
+    "@eslint/js": "^9.39.1",
+    "@types/node": "^24.10.1",
+    "@types/react": "^19.2.7",
+    "@types/react-dom": "^19.2.3",
+    "@vitejs/plugin-react": "^5.1.1",
+    "eslint": "^9.39.1",
+    "eslint-plugin-react-hooks": "^7.0.1",
+    "eslint-plugin-react-refresh": "^0.4.24",
+    "globals": "^16.5.0",
+    "typescript": "~5.9.3",
+    "typescript-eslint": "^8.48.0",
+    "vite": "^7.3.1"
+  }
+}