fix(data-service): inject REDIS_URL from ConfigMap

- Add REDIS_URL env var using variable expansion from the existing
  trading-data-service-config ConfigMap (REDIS_HOST + REDIS_PORT).
- This resolves the 'connecting to localhost:6379' crash on startup.
- Matches the actual infrastructure configuration in customer1.

apps/base/customer1/trading-platform/data-service/deployment.yaml

@@ -48,6 +48,8 @@ spec:
             - configMapRef:
                 name: trading-data-service-config
           env:
+            - name: REDIS_URL
+              value: "redis://$(REDIS_HOST):$(REDIS_PORT)/0"
             - name: DB_USER
               valueFrom:
                 secretKeyRef: