feat: add forward authentication configuration and UI

- Introduced ForwardAuthConfig model to store global forward authentication settings.
- Updated Manager to fetch and apply forward authentication configuration.
- Added ForwardAuthHandler to create a reverse proxy handler for authentication.
- Enhanced ProxyHost model to include forward authentication options.
- Created Security page and ForwardAuthSettings component for managing authentication settings.
- Implemented API endpoints for fetching and updating forward authentication configuration.
- Added tests for new functionality including validation and error handling.
- Updated frontend components to support forward authentication settings.

frontend/src/pages/Security.tsx

@@ -0,0 +1,16 @@
+import ForwardAuthSettings from '../components/ForwardAuthSettings';
+
+export default function Security() {
+  return (
+    <div className="space-y-6">
+      <div>
+        <h1 className="text-2xl font-bold text-gray-900 dark:text-white">Security</h1>
+        <p className="mt-1 text-sm text-gray-500 dark:text-gray-400">
+          Manage security settings and authentication providers.
+        </p>
+      </div>
+
+      <ForwardAuthSettings />
+    </div>
+  );
+}