What
When Claude Code is started by the VS Code extension (the entrypoint claude-vscode) and the session is non-interactive, meaning it runs a task without the usual back-and-forth chat screen, it now skips a startup call that prewarms markdown. Prewarming means preparing the part of Claude Code that formats markdown text before it is first needed. All other kinds of launch still run that call.
Why
In practice, one piece of startup work is no longer done in this one case.