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

desktop-client/src/App.tsx

@@ -0,0 +1,107 @@
+import { FormEvent, useState } from "react";
+import { invoke } from "@tauri-apps/api/core";
+
+type EnrollmentState = {
+  assignedIp: string;
+  resources: string[];
+  profileRevision: number;
+  gatewayEndpoint: string;
+};
+
+export function App() {
+  const [serverUrl, setServerUrl] = useState("http://localhost");
+  const [username, setUsername] = useState("");
+  const [password, setPassword] = useState("");
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [connected, setConnected] = useState(false);
+  const [state, setState] = useState<EnrollmentState | null>(null);
+
+  async function onSubmit(event: FormEvent) {
+    event.preventDefault();
+    setLoading(true);
+    setError(null);
+
+    try {
+      const result = await invoke<EnrollmentState>("enroll_device", {
+        payload: { serverUrl, username, password }
+      });
+      setState(result);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : "Enrollment failed");
+    } finally {
+      setLoading(false);
+    }
+  }
+
+  async function toggleConnection() {
+    const command = connected ? "disconnect_tunnel" : "connect_tunnel";
+    await invoke(command);
+    setConnected((value) => !value);
+  }
+
+  return (
+    <div className="client-shell">
+      <div className="hero">
+        <p className="eyebrow">NexaVPN</p>
+        <h1>Private access without manual WireGuard setup.</h1>
+        <p className="lede">
+          Enter your VPN address, username, and password. NexaVPN provisions and stores the profile for you.
+        </p>
+      </div>
+
+      {!state ? (
+        <form className="panel" onSubmit={onSubmit}>
+          <label>
+            VPN server address
+            <input value={serverUrl} onChange={(event) => setServerUrl(event.target.value)} />
+          </label>
+          <label>
+            Username
+            <input value={username} onChange={(event) => setUsername(event.target.value)} />
+          </label>
+          <label>
+            Password
+            <input type="password" value={password} onChange={(event) => setPassword(event.target.value)} />
+          </label>
+          {error ? <div className="error">{error}</div> : null}
+          <button disabled={loading} type="submit">
+            {loading ? "Provisioning..." : "Sign in"}
+          </button>
+        </form>
+      ) : (
+        <div className="panel status">
+          <div className="status-row">
+            <div>
+              <p className="eyebrow">Connection</p>
+              <h2>{connected ? "Connected" : "Disconnected"}</h2>
+            </div>
+            <button onClick={toggleConnection}>{connected ? "Disconnect" : "Connect"}</button>
+          </div>
+          <div className="details">
+            <div>
+              <span>Assigned VPN IP</span>
+              <strong>{state.assignedIp}</strong>
+            </div>
+            <div>
+              <span>Gateway</span>
+              <strong>{state.gatewayEndpoint}</strong>
+            </div>
+            <div>
+              <span>Profile revision</span>
+              <strong>{state.profileRevision}</strong>
+            </div>
+          </div>
+          <div>
+            <p className="eyebrow">Allowed resources</p>
+            <ul className="resource-list">
+              {state.resources.map((resource) => (
+                <li key={resource}>{resource}</li>
+              ))}
+            </ul>
+          </div>
+        </div>
+      )}
+    </div>
+  );
+}