- Use 'jq -Rs split' instead of 'jq -R' to properly handle base64 data URIs
that may contain embedded newlines in the data
- Fix double-nesting of subject_reference array causing API error 2013
- Also fix: base64 -w 0 to avoid line wrapping in base64 output
- Write payload to temp file for curl to avoid shell arg length limits
- Add full response output on API error for easier debugging
Fixes#53
9643620f1a