The link target was passed through url.PathEscape, which turns the '?' of
turn:host:3478?transport=udp into %3F. The target of a Link header field
is a URI reference and "?transport=" is part of TURN URI syntax
, not a query string, so a publisher that percent-decodes the
target ends up with an unparsable host.
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>