Report BibTeX entries from citation files and READMEs

[andrew]

Parses CITATION.bib with git-pkgs/bibtex and reports its entries in resources.bibtex. CITATION, CITATION.md and CITATION.txt are also checked for embedded BibTeX, with empty results omitted when there are no diagnostics. BibTeX in the README goes in resources.readme_bibtex. CFF and BibTeX discovery are independent, so CITATION.cff and a sibling CITATION.bib are both reported; resources.citation remains CFF-only.

Entries include type, key, title, authors, year, DOI, URL, version, journal, booktitle, publisher, volume, number, pages, eprint and source line. TeX is converted to plain Unicode. Authors use the CFF author shape, with braced organisation names in name and and others omitted. Parse diagnostics include line and column when available. Read, encoding and limit errors remain in the report even when extraction returns no entries; files over 1 MiB produce limit_exceeded.

Human and Markdown output summarise each source and its first entry; --verbose lists every entry. brief diff retains each block when its source file changed, including extraction errors. brief schema includes the new types.

The BibTeX dependency is pinned to v0.1.0, which fixes Windows-1252 macro decoding, extraction after a UTF-8 BOM and recovery at blockquote code fences.

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