wfctl v0.74.3 validate-contract rejects provider descriptor contracts array

[intel352]

Summary

wfctl plugin validate-contract --for-publish in v0.74.3 rejects workflow-plugin-product-capture's current plugin.json.contracts shape. The same release gate had been using wfctl v0.63.2 successfully.

Observed

During workflow-plugin-product-capture tag v0.1.8, the release workflow installed wfctl v0.74.3 successfully, then failed in Validate plugin contract for publish (pre-build):

wfctl plugin validate-contract: FAIL
  - invalid_plugin_contract_descriptors: json: cannot unmarshal array into Go value of type main.pluginContractDescriptorFile

Run: https://github.com/GoCodeAlone/workflow-plugin-product-capture/actions/runs/27055537342

Reproduction Shape

plugin.json contains provider contract descriptors inline:

"contracts": [
  {
    "id": "product-capture.browser.v1",
    "path": "contracts/product-capture-provider.json",
    "schema": "schemas/product-capture-provider.schema.json"
  }
]

wfctl v0.74.3 appears to parse inline plugin.json.contracts as pluginContractDescriptorFile, which expects an object with a contracts field rather than this existing array shape.

Impact

Product-capture release had to forward-fix with a new tag (v0.1.9) and restore the release workflow validator pin to wfctl v0.63.2. The failed v0.1.8 tag is immutable and remains as evidence.

Expected

Either:

• validate-contract should continue accepting the existing provider descriptor array shape when used in plugin.json.contracts, or
• the validator/docs should distinguish strict plugin contract descriptors from provider contract descriptors and provide a migration path before release gates move to v0.74.x.