`get_languages` computed `desired_width = term_width - longest - separator.len()`.
When `--terminal-width` is smaller than the longest language name (e.g. 1), this
underflows `usize`: in overflow-checked builds it panics ("attempt to subtract with
overflow"), and in release it wraps to ~usize::MAX, silently disabling the extension
line-wrapping so `--terminal-width` is ignored for `--list-languages`.
Use `saturating_sub`, mirroring the fix applied to `print_snip` in #3804 (the snip
separator had the same `term_width - ...` underflow pattern). Output at normal widths
is unchanged.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
greymoth