extraManifests.kind breaks ArgoCD unless capitalized

[barsilver]

Hi,

When using the provided values_full.yaml from the examples folder with ArgoCD, I encountered this error:

InvalidSpecError: Unable to generate manifests in .: 
rpc error: code = FailedPrecondition desc = Failed to unmarshal "n8n_values.yaml": 
failed to unmarshal manifest: error unmarshaling JSON: 
while decoding JSON: Object 'Kind' is missing in '{"extraManifests":[{"apiVersion":"postgresql.cnpg.io/v1","kind":"Cluster","metadata":{"name":"db"},"spec":{"instances":1,"bootstrap":{"initdb":{"database":"n8n","owner":"n8n"}},"postgresql":{"parameters":{"shared_buffers":"64MB"}},"resources":{"requests":{"memory":"512Mi"},"limits":{"memory":"512Mi"}},"storage":{"size":"1Gi"}}}]}'

After some testing, I discovered that ArgoCD fails to parse the extraManifests section unless the kind field is capitalized (Kind instead of kind).
For example:

extraManifests:
  - apiVersion: postgresql.cnpg.io/v1
    Kind: Cluster   # <-- works
    metadata:
      name: db
    spec:
      instances: 1
      bootstrap:
        initdb:
          database: n8n
          owner: n8n
      postgresql:
        parameters:
          shared_buffers: "64MB"
      resources:
        requests:
          memory: "512Mi"
        limits:
          memory: "512Mi"
      storage:
        size: 1Gi

With the lowercase kind: cluster, ArgoCD throws the error above.
Interestingly, this does not happen with helm template. helm template works fine even with the lowercase kind.

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Expected behavior:
The example values_full.yaml should work out of the box with ArgoCD, without requiring manual capitalization fixes.

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Environment:

Helm version: v3.18.4

ArgoCD version: 8.3.7

Kubernetes version: 1.31