improvement: treatment UX fully overhauled.

frontend/src/app/[locale]/(dashboard)/layout.tsx

@@ -90,7 +90,7 @@ export default function DashboardLayout({ children }: { children: React.ReactNod
           onOpenSidebar={() => setSidebarOpen(true)}
         />
 
-        <main className="p-3 sm:p-4 lg:p-6 flex-1 min-h-0 overflow-y-auto">
+        <main className="p-3 sm:p-4 lg:p-6 flex-1 min-h-0 overflow-y-auto overscroll-y-contain">
           <div className="surface-panel p-3 sm:p-4 lg:p-6 min-w-0">
             {children}
           </div>