[codex] Improve dry run output configuration

[Eis4TY]

Summary

• Add user-configurable API output fields with JSONPath and text/json extraction modes.
• Fix Dry Run parsing for ordinary JSON responses and final stream buffers without trailing newlines.
• Add unified client-side handling for unauthorized API responses.
• Move status, end reason, error type, and error message columns to the end of result tables and exports.
• Remove private example endpoints from open-source defaults and require explicit auth secrets in production.

Validation

• npm run lint
• npx tsc --noEmit

Notes

Created as a draft for review.