split Strimzi operator into separate kustomization for Flux dependsOn

Flux dry-run fails when CRDs are in the same kustomization as resources
that reference them - CRDs need to exist before validation.

Two kustomizations now:
  strimzi/        - Strimzi 1.0.0 CRDs + operator
  siriusdevops-db - DBs, Kafka CR (depends on strimzi CRDs)

Wire them in Flux:
  Kustomization 'siriusdevops-strimzi' -> path: strimzi/
  Kustomization 'siriusdevops-db'      -> path: siriusdevops-db/
    dependsOn: [{name: siriusdevops-strimzi}]

apps/base/customer1/siriusdevops-db/kustomization.yaml

@@ -11,7 +11,5 @@ resources:
   # Trading platform DB (migrated from hermes-pgdb)
   - trading-db-credentials.yaml
   - trading-data-db.yaml
-  # Strimzi Kafka operator (CRDs + operator deployment)
-  - https://strimzi.io/install/1.0.0?namespace=customer1
-  # Kafka cluster (applied after operator CRDs are available)
+  # Kafka cluster (depends on strimzi/ kustomization for CRDs)
   - trading-kafka.yaml

apps/base/customer1/siriusdevops-db/strimzi/kustomization.yaml

@@ -0,0 +1,6 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+  # Strimzi Kafka operator - CRDs + cluster operator
+  # Pinned to 1.0.0 for reproducible deployments
+  - https://strimzi.io/install/1.0.0?namespace=customer1