Fix TypeScript errors for GitHub Actions build

- Add 'normal' skill type to SKILL_ICONS constant
- Fix parseInt undefined error in UserPage by providing default value
- Ensure type safety for Card skill property
- API URL correctly configured for production (https://api.syui.ai/)

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

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

src/components/pages/UserPage.tsx

@@ -59,7 +59,7 @@ export default function UserPage() {
             {/* Favorite Card Section */}
             {user.fav && user.fav !== '0' && cards?.data && (
               (() => {
-                const favCard = cards.data.find(card => card.id === parseInt(user.fav));
+                const favCard = cards.data.find(card => card.id === parseInt(user.fav || '0'));
                 if (favCard) {
                   return (
                     <div className="mb-8">