style(desktop): primitive-level pointer cursor + borderless settings lists

Add a base-layer rule giving every interactive control (button, select,
menu item, switch, tab, summary) cursor:pointer, and strip the now-redundant
hardcoded cursor-pointer from those elements (plain clickable divs/labels
keep theirs). Remove the divide-y separators from settings list sections so
they breathe.

apps/desktop/src/components/notifications.tsx

@@ -132,7 +132,7 @@ function NotificationItem({ notification }: { notification: AppNotification }) {
 function NotificationDetail({ detail }: { detail: string }) {
   return (
     <details className="mt-2 text-xs text-muted-foreground">
-      <summary className="cursor-pointer select-none font-medium text-muted-foreground hover:text-foreground">
+      <summary className="select-none font-medium text-muted-foreground hover:text-foreground">
         Details
       </summary>
       <div className="mt-1 rounded-md border border-border/70 bg-background/65 p-2">