M5b review, findings 1 and 2. url_len ended a clean reply's URL at any
`<` outside parentheses, not at a `<` before white space, a bracket,
`<`, `>` or the end; closes used a count of characters as a byte
offset, so a closer indented with a no-break space did not close its
fence. Both bodies, and fence_end's (an index replaced by `get`), are
the reference's again. tests/links_review.rs pins both cases with the
reference's output.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
