M3 wants two visual indicators per state and names the pair for a text field: the error colours and a trailing error icon. The field now draws one, labelled "Error", unless the caller already trails it or the field is xs. A read-only field loses its dashed outline: M3 keeps "the same visual style as an editable field", and the native readonly attribute is what tells a screen reader. The data-readonly hook stays. Plan step 20, findings IN-18 and IN-19. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9