feat: add health check endpoint and Docker health monitoring

Add a /health endpoint to the application controller and configure Docker health checks.
This enables container orchestration systems to monitor the application's liveness and readiness.

dist/app.controller.d.ts

@@ -9,4 +9,7 @@ export declare class AppController {
     register(): {};
     registerPost(body: any, res: Response, req: any): Promise<void>;
     logout(req: any, res: Response): void;
+    health(): {
+        status: string;
+    };
 }