feat(iframe): add iframe bridge for ragflow integration

- Implement Penpal-based iframe communication bridge between host and child apps
- Add route handling for ragflow integration with '/route-ragflow' prefix
- Update navigation hooks to support embedded mode via iframe bridge
- Configure build and dependencies for new iframe-bridge package
- Adjust nginx config for proper SPA routing in subpath deployments

packages/iframe-bridge/tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "extends": "../../tsconfig.node.json",
+  "compilerOptions": {
+    "outDir": "dist",
+    "rootDir": "src",
+    "tsBuildInfoFile": "./dist/.tsbuildinfo",
+    "composite": true,
+    "noEmit": false,
+    "lib": ["ES2022", "DOM", "DOM.Iterable"],
+    "allowImportingTsExtensions": false,
+    "declaration": true,
+    "declarationMap": true
+  },
+  "include": ["src"]
+}