fix: add missing newlines at the end of JSON files; clean up formatting in page components

packages/ui/src/shadcn/collapsible.tsx

@@ -2,6 +2,8 @@
 
 import { Collapsible as CollapsiblePrimitive } from '@base-ui/react/collapsible';
 
+import { cn } from '../lib/utils';
+
 function Collapsible({ ...props }: CollapsiblePrimitive.Root.Props) {
   return <CollapsiblePrimitive.Root data-slot="collapsible" {...props} />;
 }
@@ -12,9 +14,31 @@ function CollapsibleTrigger({ ...props }: CollapsiblePrimitive.Trigger.Props) {
   );
 }
 
-function CollapsibleContent({ ...props }: CollapsiblePrimitive.Panel.Props) {
+/**
+ * CollapsibleContent (Panel) with smooth height animation.
+ *
+ * Base UI sets `--collapsible-panel-height` automatically and provides
+ * `data-open`, `data-closed`, `data-starting-style`, `data-ending-style`
+ * for CSS-driven animations.
+ */
+function CollapsibleContent({
+  className,
+  ...props
+}: CollapsiblePrimitive.Panel.Props) {
   return (
-    <CollapsiblePrimitive.Panel data-slot="collapsible-content" {...props} />
+    <CollapsiblePrimitive.Panel
+      data-slot="collapsible-content"
+      className={cn(
+        [
+          'h-(--collapsible-panel-height) overflow-hidden transition-[height] duration-200 ease-out',
+          'data-[closed]:h-0',
+          'data-[starting-style]:h-0',
+          'data-[ending-style]:h-0',
+        ],
+        className,
+      )}
+      {...props}
+    />
   );
 }