Verify one or a small batch of citations

Checks a citation against 6 academic databases (OpenAlex, Crossref, Semantic Scholar, PubMed, DBLP, arXiv) to see if it's accurate, not found, or has mismatches. Provide exactly one of text, texts, citation, or citations. text/texts is a raw citation string (or a batch of up to 10), parsed via LLM extraction; it can be a formatted bibliographic citation or a bare URL -- a URL that isn't in an academic database is fetched directly and its title/author text is confirmed to appear on the page, rather than matched against a bibliographic record. citation/citations instead takes already-structured bib-style fields (title/author/year/doi/journal/volume/issue/page/publisher/url/type) and skips the LLM parse entirely -- use this if you already have structured metadata (e.g. from your own .bib file). Batch items are verified in parallel, so response time is close to that of a single citation rather than growing with batch size. Rate limit: 60 requests/minute per API key.