Disclose Codex asset authorship

[ael-dev3]

Summary

• add a visible creation-process disclosure beside the repository's license guidance
• disclose that most archived assets were substantially authored, prepared, or refined with Codex using GPT-5.6 Sol at Ultra reasoning effort
• preserve the role of human direction, other creation tools, and set-specific provenance
• clarify that the disclosure does not alter licensing, ownership, attribution, or trademark boundaries
• add regression coverage so the disclosure is not silently removed or blurred

Validation

• python3 -m compileall -q -f scripts tests
• python3 -m unittest discover -s tests -v — 35 tests passed
• git diff --check