chore: install @xyflow/react and @dagrejs/dagre

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

frontend/package.json

@@ -13,12 +13,14 @@
     "analyze": "vite-bundle-visualizer"
   },
   "dependencies": {
+    "@dagrejs/dagre": "^2.0.4",
     "@dnd-kit/core": "^6.3.1",
     "@dnd-kit/sortable": "^10.0.0",
     "@dnd-kit/utilities": "^3.2.2",
     "@monaco-editor/react": "^4.7.0",
     "@stripe/stripe-js": "^8.7.0",
     "@types/lodash": "^4.17.23",
+    "@xyflow/react": "^12.10.0",
     "axios": "^1.13.4",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",