Validate Bibliography

Cross-reference citations in lecture files against bibliography entries. Two modes:

• Default (structural): missing entries, unused entries, malformed fields, typo candidates.
• --semantic: adds citation-drift detection (duplicate entries for the same paper), DOI verification via crossref, and citation-style consistency within each file.

Report saved to quality_reports/bib_audit_[structural|semantic].md.

Mode 1: Structural (default)

Steps

1. Read the bibliography file and extract all citation keys.

2. Scan lecture files for citation keys:

   • .tex: \cite{, \citet{, \citep{, \citeauthor{, \citeyear{, \textcite{, \parencite{
   • .qmd / .md: @key, [@key], [@key1; @key2]
   • Extract all unique citation keys used.