fix: update healthcheck to use 127.0.0.1 instead of localhost

Updated Docker healthcheck to use 127.0.0.1 for better compatibility.

Deployment target: https://audio.kit.pivoine.art

Dockerfile

@@ -35,7 +35,7 @@ EXPOSE 80
 
 # Health check
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
-  CMD wget --quiet --tries=1 --spider http://localhost/ || exit 1
+  CMD wget --quiet --tries=1 --spider http://127.0.0.1/ || exit 1
 
 # Start nginx
 CMD ["nginx", "-g", "daemon off;"]