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

deploy/scripts/gateway-entrypoint.sh

@@ -0,0 +1,8 @@
+#!/bin/sh
+set -eu
+
+echo "NexaVPN gateway helper starting"
+echo "This container is a placeholder for WireGuard + nftables sync logic."
+echo "Mount generated gateway state into /var/lib/nexavpn and apply rules from there."
+
+tail -f /dev/null