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/bootstrap-admin.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+set -eu
+
+cat <<'EOF'
+Bootstrap flow:
+1. Run backend migrations from backend/migrations.
+2. Seed roles and default settings from backend/seed/001_seed.sql.
+3. Insert the first admin user with an Argon2id password hash generated by the backend auth package or a one-off helper.
+EOF