fix(otel): use OTLP HTTP/protobuf to tempo:4318 instead of gRPC:4317

Stack trace showed io.opentelemetry.exporter.internal.http.HttpExporter
sending to :4317 — Tempo on 4317 expects gRPC frames, gets HTTP, sends
RST. Switch endpoint to :4318 (Tempo OTLP HTTP receiver) and protocol to
http/protobuf so the SDK and Tempo speak the same protocol.

The gRPC config never took effect — Spring Boot SDK on micrometer-tracing-
otlp pulls in only the HTTP exporter by default; gRPC needs the explicit
opentelemetry-exporter-otlp jar.

ordinis-app/src/main/resources/application.yml

@@ -36,8 +36,8 @@ management:
 otel:
   exporter:
     otlp:
-      endpoint: ${OTEL_EXPORTER_OTLP_ENDPOINT:http://tempo.monitoring:4317}
-      protocol: grpc
+      endpoint: ${OTEL_EXPORTER_OTLP_ENDPOINT:http://tempo.monitoring:4318}
+      protocol: http/protobuf
   resource:
     attributes:
       service.name: ${spring.application.name}