8 real requests sent to the running app:
  $ for i in $(seq 1 8); do curl -s -X POST "http://localhost:8080/orders/$i"; done

Queried straight from the real Prometheus-compatible API bundled inside the grafana/otel-lgtm
container -- not the app's own /actuator endpoint, not a mock:

  $ curl -s "http://localhost:9090/api/v1/query?query=orders_placed_total"
  {
    "status": "success",
    "data": {
      "resultType": "vector",
      "result": [
        {
          "metric": {
            "__name__": "orders_placed_total",
            "application": "order-service",
            "channel": "web",
            "job": "order-service",
            "service_name": "order-service"
          },
          "value": [1789722945.151, "8"]
        }
      ]
    }
  }

Every one of the 8 POSTs landed as a real OTLP metric, pushed over the network, through the
Docker Compose auto-wired endpoint, and queried back out of the real Prometheus-compatible
backend Grafana LGTM bundles.