fix(hackathon): match search input height with city select and add debounce

- Set consistent h-[42px] height for both search and city filter inputs
- Add 300ms debounce to search to reduce API calls while typing

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

Co-Authored-By: Claude <noreply@anthropic.com>

apps/hackathon/src/components/city-select.tsx

@@ -70,7 +70,7 @@ export const CitySelect: FC<CitySelectProps> = ({
           }}
           onClick={handleInputClick}
           placeholder={placeholder}
-          className={`w-full px-3 py-2 border rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-transparent ${
+          className={`w-full h-[42px] px-3 border rounded-lg focus:ring-2 focus:ring-blue-500 focus:border-transparent ${
             error ? 'border-red-500' : 'border-gray-300'
           }`}
         />