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/api/proxyHosts.ts

@@ -30,6 +30,8 @@ export interface ProxyHost {
   hsts_subdomains: boolean;
   block_exploits: boolean;
   websocket_support: boolean;
+  forward_auth_enabled: boolean;
+  forward_auth_bypass: string;
   locations: Location[];
   advanced_config?: string;
   enabled: boolean;