Improve accessibility and touch support in dashboard

Enhances accessibility and usability for touch devices and Chromebooks by updating global styles, adding ARIA attributes, and optimizing component layouts. Introduces a new useIsTouchDevice hook, improves focus states, and increases viewport scalability. ChatDetail now supports better keyboard navigation and larger touch targets.

app/dashboard/chats/layout.tsx

@@ -8,6 +8,8 @@ export const metadata: Metadata = {
 export const viewport: Viewport = {
   width: "device-width",
   initialScale: 1,
+  maximumScale: 5,
+  userScalable: true,
   themeColor: [
     { media: "(prefers-color-scheme: dark)", color: "#000000" },
     { media: "(prefers-color-scheme: light)", color: "#D53F8C" },