the bubble's copy button copies the whole reply, which is the wrong unit when
the reply is prose ending in one command to run. fenced blocks get their own
button; inline code doesn't. text read from textContent at click time rather
than the markdown ast, trailing newline stripped so a pasted command doesn't
run itself. the positioned wrapper takes the vertical margin, or the pre's own
margin collapses through it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>