The send button is disabled while generation is in progress

An always-enabled send button during generation lets users submit multiple messages in rapid succession, producing race conditions where two in-flight completions interleave in the UI, one overwrites the other's state, or both consume tokens against the same conversation. This also hides the current app state from the user, who has no visual signal that a generation is already in progress and assumes their first click did not register.

In src/components/chat/ChatInput.tsx, bind the button's disabled attribute to the loading state and add visible disabled styling (reduced opacity, not-allowed cursor) so the state change is obvious. Optionally disable the textarea itself during generation.

<Button type="submit" disabled={isLoading} className="disabled:opacity-50 disabled:cursor-not-allowed">
  Send
</Button>