feat: add slideDown animation for upward-flipping popovers

packages/web/src/styles/globals.css

@@ -325,6 +325,16 @@
   animation: slideUp 0.15s ease-out;
 }
 
+/* Slides into place from above — used for popovers that open upward */
+@keyframes slideDown {
+  from { transform: translateY(-10px); opacity: 0; }
+  to { transform: translateY(0); opacity: 1; }
+}
+
+.animate-slide-down {
+  animation: slideDown 0.15s ease-out;
+}
+
 @keyframes typingFadeIn {
   from { transform: translateY(4px); opacity: 0; }
   to { transform: translateY(0); opacity: 1; }