fix: use 127.0.0.1 in web healthcheck to avoid IPv6 issues

wget resolves 'localhost' to IPv6 [::1] but nginx only listens on
IPv4 0.0.0.0:80, causing connection refused. Using 127.0.0.1 ensures
IPv4 connection and healthy container status.

apps/web/Dockerfile

@@ -40,7 +40,7 @@ EXPOSE 80
 
 # Health check
 HEALTHCHECK --interval=30s --timeout=10s --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;"]