The handler carried four guards, a preventDefault and a state
transition inline in the TextInput's props, which is what AGENTS.md
rules out ("NEVER use inline code; instead extract to functions in the
same file"). Name it handleEnlargeKeyDown and put it beside
enlargeWithNewline, where the comment can enumerate why each condition
is there rather than sitting between two JSX props.
No behavior change.
Signed-off-by: cliffhall <cliff@futurescale.com>