Kafka 백킹서비스 설치 디렉토리 추가

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

backing-service/install/kafka/kafka-external.yaml

@@ -0,0 +1,17 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: kafka-external
+  namespace: kt-event-marketing
+spec:
+  ports:
+  - name: tcp-client
+    port: 9092
+    protocol: TCP
+    targetPort: client
+  selector:
+    app.kubernetes.io/instance: kafka
+    app.kubernetes.io/name: kafka
+    app.kubernetes.io/part-of: kafka
+  sessionAffinity: None
+  type: LoadBalancer