Fix modal scroll position jumps (#542)

Preserve page scroll positions while Radix modals acquire focus and forward the dialog overlay ref correctly.

vite-frontend/src/components/ui/dialog.tsx

@@ -28,12 +28,13 @@ function DialogClose({
   return <DialogPrimitive.Close data-slot="dialog-close" {...props} />;
 }
 
-function DialogOverlay({
-  className,
-  ...props
-}: React.ComponentProps<typeof DialogPrimitive.Overlay>) {
+const DialogOverlay = React.forwardRef<
+  React.ElementRef<typeof DialogPrimitive.Overlay>,
+  React.ComponentPropsWithoutRef<typeof DialogPrimitive.Overlay>
+>(({ className, ...props }, ref) => {
   return (
     <DialogPrimitive.Overlay
+      ref={ref}
       className={cn(
         "fixed inset-0 z-50 bg-black/30 backdrop-blur-md data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0",
         className,
@@ -42,7 +43,9 @@ function DialogOverlay({
       {...props}
     />
   );
-}
+});
+
+DialogOverlay.displayName = DialogPrimitive.Overlay.displayName;
 
 function DialogContent({
   className,