fix(admin): mount popover portal inside app container

Instead of mounting to body (which breaks scoped styles), we now
mount the popover portal to #woonoow-admin-app. This ensures
dropdowns inherit the correct CSS variables and styling.

admin-spa/src/components/ui/popover.tsx

@@ -13,7 +13,7 @@ const PopoverContent = React.forwardRef<
   React.ElementRef<typeof PopoverPrimitive.Content>,
   React.ComponentPropsWithoutRef<typeof PopoverPrimitive.Content>
 >(({ className, align = "center", sideOffset = 4, ...props }, ref) => (
-  <PopoverPrimitive.Portal>
+  <PopoverPrimitive.Portal container={document.getElementById("woonoow-admin-app")}>
     <PopoverPrimitive.Content
       ref={ref}
       align={align}