Add Ping frontend

React 19 + TypeScript client built with Vite. Zustand for local state,
react-oidc-context for the login flow, a SignalR connection for chat and
presence events, and LiveKit's React components for voice/video calls.

frontend/package.json

@@ -0,0 +1,33 @@
+{
+  "name": "frontend",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc -b && vite build",
+    "lint": "oxlint",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "@livekit/components-react": "^2.9.24",
+    "@livekit/components-styles": "^1.2.0",
+    "@microsoft/signalr": "^10.0.11",
+    "livekit-client": "^2.22.3",
+    "oidc-client-ts": "^3.5.0",
+    "react": "^19.2.8",
+    "react-dom": "^19.2.8",
+    "react-oidc-context": "^3.3.1",
+    "react-router-dom": "^7.18.4",
+    "zustand": "^5.0.15"
+  },
+  "devDependencies": {
+    "@types/node": "^24.13.3",
+    "@types/react": "^19.2.18",
+    "@types/react-dom": "^19.2.7",
+    "@vitejs/plugin-react": "^6.1.1",
+    "oxlint": "^1.81.0",
+    "typescript": "~6.0.2",
+    "vite": "^8.3.0"
+  }
+}