The region carrying aria-live was created together with its message, inside the x-if that draws the snackbar, so a screen reader had nothing to notice changing. It moves to the permanent host, which is polite and atomic as M3 asks; a type now only picks the region's role, and the explicit aria-live keeps an error polite too. Plan step 11, actions.md ACT-02. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9