Refactor Clash component to use GameModal for game interactions, remove Hello World page, and implement toast notifications for error handling

crypto_clash_frontend/app/globals.css

@@ -24,3 +24,20 @@ body {
   color: var(--foreground);
   font-family: Arial, Helvetica, sans-serif;
 }
+
+@keyframes fade-in {
+  from {
+    opacity: 0;
+    transform: translateY(10px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+@layer utilities {
+  .animate-fade-in {
+    animation: fade-in 0.3s ease-out;
+  }
+}