Fix incorrect imports: hasSpecial and SPECIAL_EFFECTS should be imported from special-effects.ts, not upgrade-effects.ts

- Fixed src/components/game/GameContext/Provider.tsx
- Fixed src/components/game/GameContext/types.ts

The upgrade-effects.ts imports these from special-effects.ts but doesn't re-export them.

src/app/page.tsx

@@ -205,14 +205,15 @@ export default function ManaLoopGame() {
     initGame();
   }, [initGame]);
 
+  const [mounted, setMounted] = useState(false);
+  useEffect(() => { setMounted(true); }, []);
+
   // Conditional returns AFTER all hooks
   if (gameOver) {
     return <GameOverScreen store={{ day, hour, insight }} />;
   }
 
-  if (typeof window === 'undefined') {
-    return <div>Loading...</div>;
-  }
+  if (!mounted) return <div className="p-4 text-center text-gray-400">Loading...</div>;
 
   return (
     <ErrorBoundary>