chore: deploy frontend to summer; fix healthcheck localhost→127.0.0.1

alpine wget resolves localhost to ::1 (IPv6) but node only binds IPv4;
switched healthcheck URL to 127.0.0.1 to fix unhealthy container.

docker-compose.yml

@@ -63,7 +63,7 @@ services:
         target: /now-playing
         read_only: true
     healthcheck:
-      test: ['CMD', 'wget', '-q', '-O', '-', 'http://localhost:3000/api/stations.json']
+      test: ['CMD', 'wget', '-q', '-O', '-', 'http://127.0.0.1:3000/api/stations.json']
       interval: 30s
       timeout: 5s
       retries: 3