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.

src/app.controller.ts

@@ -64,4 +64,9 @@ export class AppController {
       res.redirect('/login');
     });
   }
+
+  @Get('health')
+  health() {
+    return { status: 'ok' };
+  }
 }