Update documentation and example values

examples/values.yaml

@@ -10,8 +10,28 @@ global:
   
   # -- Image registry for all Flow services
   imageRegistry: "cr.kn.entit.eu"
-  # -- Image pull secrets
+  # -- Image pull secrets (list of existing secret names)
   imagePullSecrets: []
+  
+  # -- Image registry credentials for private registries (e.g., Harbor)
+  # When enabled, creates a dockerconfigjson secret for pulling images
+  # This is required for Harbor even for public repositories
+  imageCredentials:
+    # -- Enable creation of image pull secret from credentials
+    enabled: false
+    # -- Registry server URL (defaults to imageRegistry if not set)
+    registry: ""
+    # -- Registry username (can use environment variable via --set global.imageCredentials.username=$HARBOR_USER)
+    username: ""
+    # -- Registry password (can use environment variable via --set global.imageCredentials.password=$HARBOR_PASSWORD)
+    password: ""
+    # -- Email for registry authentication (optional)
+    email: ""
+    # -- Name of the generated secret
+    secretName: ""
+    # -- Use existing secret instead of creating one (set to secret name to use existing)
+    existingSecret: ""
+  
   # -- Storage class for persistent volumes
   storageClass: ""