The default branch in unmarshalResponsesInputItem had two issues:
- It referenced typeField.Type instead of itemType; these differ when the
shorthand role-based format promotes an empty type to "message", meaning
an unhandled type would show the wrong value in the error string.
- It used %s formatting, so an empty type field produced the unhelpful
message "unknown input item type: " with no indication what was missing.
Fix by using itemType (the resolved value) with %q quoting, and add a
dedicated message when itemType is empty (both type and role absent):
"input item missing required 'type' field".
Tests added for the empty-type and missing-type cases.
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
In addition to strings (which we already supported), OpenResponses
supports arrays of text content, image content, or file content (see
<https://www.openresponses.org/reference#object-FunctionCallOutput-title>).
We were missing support for these arrays, which caused unmarshal errors
like
```
json: cannot unmarshal array into Go struct field ResponsesFunctionCallOutput.output of type string
```
This change adds support for text content and image content, as those
are more straightforwardly mappable to Ollama message formats (though
image and text interleaving is lost), but it's less clear what to do for
files. In the future we can partially support this by inlining
reasonably sized text files, but wanted to get this change out first.
Fixes: #15250
