Add explicit Traefik labels for S3 API routing

Coolify UI overrides SERVICE_FQDN env vars, so we need
explicit Traefik labels to route s3.b28.dev → port 9000

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

docker-compose.yml

@@ -33,6 +33,13 @@ services:
       - "9000"  # S3 API
       - "9001"  # Web Console
 
+    labels:
+      # S3 API routing (port 9000)
+      - "traefik.http.routers.minio-s3.rule=Host(`s3.b28.dev`)"
+      - "traefik.http.routers.minio-s3.entrypoints=http"
+      - "traefik.http.routers.minio-s3.service=minio-s3-service"
+      - "traefik.http.services.minio-s3-service.loadbalancer.server.port=9000"
+
     healthcheck:
       test: ["CMD", "mc", "ready", "local"]
       interval: 30s