style: animação suave nos dialogs via CSS keyframes

Substitui classes do tailwindcss-animate (não instalado) por keyframes
CSS nativos. Efeito de fade + scale (96%→100%) ao abrir e fechar,
sem conflito com o posicionamento translate do Tailwind v4.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/globals.css

@@ -294,3 +294,52 @@
   animation: none;
   mix-blend-mode: normal;
 }
+
+/* Dialog animations */
+@keyframes dialog-in {
+  from {
+    opacity: 0;
+    transform: scale(0.96);
+  }
+  to {
+    opacity: 1;
+    transform: scale(1);
+  }
+}
+
+@keyframes dialog-out {
+  from {
+    opacity: 1;
+    transform: scale(1);
+  }
+  to {
+    opacity: 0;
+    transform: scale(0.96);
+  }
+}
+
+@keyframes overlay-in {
+  from { opacity: 0; }
+  to   { opacity: 1; }
+}
+
+@keyframes overlay-out {
+  from { opacity: 1; }
+  to   { opacity: 0; }
+}
+
+[data-slot="dialog-overlay"][data-state="open"] {
+  animation: overlay-in 0.2s ease-out;
+}
+
+[data-slot="dialog-overlay"][data-state="closed"] {
+  animation: overlay-out 0.15s ease-in;
+}
+
+[data-slot="dialog-content"][data-state="open"] {
+  animation: dialog-in 0.25s cubic-bezier(0.16, 1, 0.3, 1);
+}
+
+[data-slot="dialog-content"][data-state="closed"] {
+  animation: dialog-out 0.15s ease-in;
+}