Get all Zenodo links: real hyperlinks from the paper's own url table,
plus a body-text fallback for a BARE mention (a DOI like
"10.5281/zenodo.1234567" is routinely cited without any URL scheme at all)
that the source PDF/HTML never encoded as an actual hyperlink — the url
table only ever contains links the source document itself made clickable.
Same two-tier approach github_links() uses for GitHub.
Examples
paper <- demopaper()
zenodo_links(paper)
#> # A tibble: 0 × 7
#> # ℹ 7 variables: href <chr>, link_text <chr>, text_id <int>, paper_id <chr>,
#> # zenodo_url <chr>, zenodo_id <chr>, zenodo_link <lgl>