chore(deps): upgrade NestJS and related dependencies to version 11.x

fix(auth): ensure JWT_SECRET is set in JwtStrategy constructor

backend/src/auth/jwt.strategy.ts

@@ -7,10 +7,15 @@ export class JwtStrategy extends PassportStrategy(Strategy) {
   private readonly logger = new Logger(JwtStrategy.name);
 
   constructor() {
+    const jwtSecret = process.env.JWT_SECRET;
+    if (!jwtSecret) {
+      throw new Error('JWT_SECRET is not set');
+    }
+
     super({
       jwtFromRequest: ExtractJwt.fromAuthHeaderAsBearerToken(),
       ignoreExpiration: false,
-      secretOrKey: process.env.JWT_SECRET,
+      secretOrKey: jwtSecret,
     });
   }