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/App.tsx

@@ -13,6 +13,7 @@ const ProxyHosts = lazy(() => import('./pages/ProxyHosts'))
 const RemoteServers = lazy(() => import('./pages/RemoteServers'))
 const ImportCaddy = lazy(() => import('./pages/ImportCaddy'))
 const Certificates = lazy(() => import('./pages/Certificates'))
+const Security = lazy(() => import('./pages/Security'))
 const SystemSettings = lazy(() => import('./pages/SystemSettings'))
 const Account = lazy(() => import('./pages/Account'))
 const Settings = lazy(() => import('./pages/Settings'))
@@ -50,6 +51,7 @@ export default function App() {
               <Route path="uptime" element={<Uptime />} />
               <Route path="notifications" element={<Notifications />} />
               <Route path="import" element={<ImportCaddy />} />
+              <Route path="security" element={<Security />} />
 
               {/* Settings Routes */}
               <Route path="settings" element={<Settings />}>