feat: standalone web UI (React + Vite)

React + TypeScript UI on port 5274. Connects to local daemon via
WebSocket IPC (DaemonAdapter). Full chat layout with sidebar, message
pane, and peer list. Mirrors the TUI feature set.

- src/types.ts        — IPC types mirroring proto.go
- src/adapter/daemon  — WebSocket IPC adapter with auto-reconnect
- src/store/index.ts  — Zustand store; handles all daemon events
- src/pages/          — Onboarding (connect + join) and Chat
- src/components/     — Sidebar, MessagePane, PeerList

Dev: cd web && npm run dev  (port 5274)
Build: cd web && npm run build

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

web/package.json

@@ -0,0 +1,31 @@
+{
+  "name": "web",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc -b && vite build",
+    "lint": "eslint .",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "react": "^19.2.6",
+    "react-dom": "^19.2.6",
+    "zustand": "^5.0.14"
+  },
+  "devDependencies": {
+    "@eslint/js": "^10.0.1",
+    "@types/node": "^24.12.3",
+    "@types/react": "^19.2.14",
+    "@types/react-dom": "^19.2.3",
+    "@vitejs/plugin-react": "^6.0.1",
+    "eslint": "^10.3.0",
+    "eslint-plugin-react-hooks": "^7.1.1",
+    "eslint-plugin-react-refresh": "^0.5.2",
+    "globals": "^17.6.0",
+    "typescript": "~6.0.2",
+    "typescript-eslint": "^8.59.2",
+    "vite": "^8.0.12"
+  }
+}