- Return the ResourceNotFoundError detail from get_civitai_versions and
get_model_versions_status instead of a bare "Model not found", and let
the download modal display the server-provided message
- Anchor extract_civitai_image_id / extractCivitaiImageId to
^/images/<id> so API paths and partial numeric IDs are rejected, same
as the model-page parsing fix in #1140