Why this change?

ZMQ write() sends raw NumPy values to send_json_with_retry(), which is not JSON-serializable. This causes ZMQ messages to fail silently when payloads include NumPy scalars or arrays. File-based write() already normalizes NumPy types, so behavior is inconsistent.

What was the problem?

• ZMQ path in concore.write() sends raw val
• JSON serialization fails for numpy.float64, numpy.int64, arrays, dicts with NumPy values
• Mixed or ZMQ-only studies break at runtime without a clear error

How I solved it

1. Normalized ZMQ payloads using convert_numpy_to_python() before send_json_with_retry()
2. Added a regression test that mocks a ZMQ port and asserts plain Python types are sent
3. Fixed a mkconcore.py regression from latest dev where absolute output paths were rejected by safe_name (needed for CLI test to pass)

Changes / Implementation

• concore.py
  • Convert NumPy values before ZMQ JSON send
• tests/test_concore.py
  • New TestWriteZMQ to verify conversion and JSON-safe payload
• mkconcore.py
  • Allow full paths for output directory in safe_name while still blocking shell metacharacters

How to Test Locally

python -m pytest -v tests/test_concore.py
python -m pytest -v

PR Checklist

• Added tests for the new behavior
• Ran full test suite locally
• No public API changes
• Fix is backwards-compatible