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/src/features/dashboard/DashboardPage.tsx

@@ -0,0 +1,36 @@
+import { Card } from "../../components/Card";
+import { Page } from "../../components/Page";
+
+export function DashboardPage() {
+  return (
+    <Page title="Dashboard" subtitle="Operational visibility across users, devices, gateways, and policy activity.">
+      <div className="grid three">
+        <Card>
+          <p className="metric-label">Active users</p>
+          <strong className="metric-value">248</strong>
+          <span>12 enrolled this week</span>
+        </Card>
+        <Card>
+          <p className="metric-label">Connected devices</p>
+          <strong className="metric-value">181</strong>
+          <span>7 pending rotation</span>
+        </Card>
+        <Card>
+          <p className="metric-label">Gateway health</p>
+          <strong className="metric-value">Healthy</strong>
+          <span>Last sync 36s ago</span>
+        </Card>
+      </div>
+      <div className="grid two">
+        <Card>
+          <h4>Recent enrollments</h4>
+          <p>New devices are issued profiles automatically after successful sign-in.</p>
+        </Card>
+        <Card>
+          <h4>Policy posture</h4>
+          <p>Gateway enforcement is generated from effective allow-lists backed by nftables.</p>
+        </Card>
+      </div>
+    </Page>
+  );
+}