fix(settings): move content padding inside scroll areas to keep inner borders visible

The settings shell wrapped children in an outer section with p-3/p-4 padding.
With OverlayScrollbars replacing native scroll, the overlay scrollbar sat at
the viewport's right edge and covered the right border of inner cards.

Drop the outer padding (and the now-redundant overflow-auto) from the shell
and apply p-3 md:p-4 inside each settings page instead, so the scrollbar
aligns with the column edge while inner sections stay within the padded area.

src/components/settings/system-network-settings.tsx

@@ -343,7 +343,7 @@ export function SystemNetworkSettings() {
 
   return (
     <ScrollArea className="h-full">
-      <div className="w-full space-y-4">
+      <div className="w-full space-y-4 p-3 md:p-4">
         <section className="space-y-1">
           <div className="flex items-center justify-between">
             <h1 className="text-sm font-semibold">{t("sectionTitle")}</h1>