- Add validation that `json_schema.schema` is present when using
`response_format.type: "json_schema"`. Previously, a missing schema
would silently result in an empty schema `{}` being used, which
matches any JSON and doesn't constrain the output.
- Update the error message for invalid response_format types to
include "json_schema" as a valid option (was only listing "text"
and "json_object").
Fixes: https://github.com/ggml-org/llama.cpp/issues/10732
1549bcee25