chore: initial project scaffold with admin web, backend, desktop client, and deployment setup

Add monorepo structure for NexaVPN WireGuard control plane including:
- .gitignore for node_modules, build artifacts, and environment files
- README with project overview, monorepo layout, and quick start guide
- Admin web UI with React, Vite, TypeScript, and nginx reverse proxy
- API client with type definitions for users, devices, policies, gateways, and audit logs
- Admin pages for dashboard, users, devices, policies, g

admin-web/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "nexavpn-admin-web",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc -b && vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "@tanstack/react-query": "^5.66.8",
+    "react": "^18.3.1",
+    "react-dom": "^18.3.1",
+    "react-router-dom": "^6.30.0"
+  },
+  "devDependencies": {
+    "@types/react": "^18.3.20",
+    "@types/react-dom": "^18.3.6",
+    "@vitejs/plugin-react": "^4.3.4",
+    "typescript": "^5.8.2",
+    "vite": "^6.2.2"
+  }
+}