fix: address PR review findings for quarkus skills

- Add missing objectMapper field to EventService example (quarkus-patterns)
- Fix eventService.validate() → documentValidator.validate() API mismatch (quarkus-tdd)
- Add DocumentValidator mock declaration in Camel route test (quarkus-tdd)
- Update .opencode java-reviewer.txt to mention Quarkus alongside Spring Boot

skills/quarkus-patterns/SKILL.md

@@ -156,6 +156,7 @@ public class ProcessingService {
 @RequiredArgsConstructor
 public class EventService {
     private final EventRepository eventRepository;
+    private final ObjectMapper objectMapper;
     
     public void createSuccessEvent(Object payload, String eventType) {
         Event event = new Event();