fix: restore animations and replace tailwind.config.ts

- tailwind.config.ts is not actually being used so removed
- moved animate-fade-in to globals.css
- added tw-animate-css package to make animate-in work
- added a definition for animate-shake as it doesn't exist in tw-animate-css

app/globals.css

@@ -1,4 +1,5 @@
 @import "tailwindcss";
+@import "tw-animate-css";
 
 @custom-variant dark (&:where(.dark, .dark *));
 
@@ -558,6 +559,40 @@ body {
   overscroll-behavior: none;
 }
 
+/* Shake animation (for rejected input) */
+@keyframes shake {
+  0%,
+  100% {
+    transform: translateX(0);
+  }
+  20%,
+  60% {
+    transform: translateX(-4px);
+  }
+  40%,
+  80% {
+    transform: translateX(4px);
+  }
+}
+
+.animate-shake {
+  animation: shake 0.4s ease-in-out;
+}
+
+/* Fade in animation (for popovers) */
+@keyframes fade-in {
+  from {
+    opacity: 0;
+  }
+  to {
+    opacity: 1;
+  }
+}
+
+.animate-fade-in {
+  animation: fade-in 0.2s ease-out;
+}
+
 /* Slide in from right animation (for mobile views) */
 @keyframes slide-in-from-right {
   from {