feat: Add placeholder text to input field

- Add "Talk to the cat..." placeholder to guide user interaction
- Improve user experience with helpful input prompt

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: koki-develop

src/components/InputField.tsx

@@ -23,6 +23,7 @@ export const InputField: React.FC<InputFieldProps> = ({
         onChange={onChange}
         onSubmit={onSubmit}
         showCursor={showCursor}
+        placeholder="Talk to the cat..."
       />
     </Box>
   );