* Initial plan
* Add keywords_in_refs: allow reserved keywords as dot-notation field names
* Address review feedback: improve parse_ref_field doc comment and clean up test comment
* Add complex keyword-in-ref test cases
* Polish keyword-ref test expectations and validate coverage
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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>