Keyboard shortcuts are available for power users

WCAG 2.2 SC 2.1.1 requires all functionality to be operable via keyboard. AI chat products that force mouse interaction exclude keyboard-dependent users — people with motor disabilities, power users, and developers who never leave the keyboard. The minimum bar — Enter to submit, Shift+Enter for newline — is so widely expected that its absence signals an incomplete implementation. Products missing it consistently receive poor reviews from technical evaluators and fail accessibility audits that gate enterprise procurement.

Add an onKeyDown handler to the chat textarea that at minimum handles Enter (submit) and Shift+Enter (newline). Wire Escape to the stop handler when streaming is active. Both are zero-dependency additions to src/components/chat/ChatInput.tsx.

const handleKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>) => {
  if (e.key === 'Enter' && !e.shiftKey) {
    e.preventDefault()
    handleSubmit()
  }
  if (e.key === 'Escape' && isLoading) {
    stop()
  }
}

<textarea
  onKeyDown={handleKeyDown}
  placeholder="Message (Enter to send, Shift+Enter for newline)"
/>

Document the shortcuts in a tooltip or placeholder text — discoverability is half the value.