feat(ui): make dashboard responsive for iPhone and mobile devices

- Add Sheet primitive component for mobile drawers
- Add MobileNav with hamburger menu for dashboard layout
- Hide desktop sidebars on mobile; show mobile header
- Make dashboard header responsive with stacked layout on small screens
- Hide selector text on mobile, show icons only
- Convert fixed-width filters to responsive widths (CFDI, Clientes, Admin, Documentos, Alertas)
- Cap dialog widths to 95vw on mobile (CFDI viewer, Documentos, Reportes, Contribuyentes, Facturación)
- Make calendar grid smaller and use single-letter weekdays on mobile
- Update viewport to include viewport-fit=cover for Samsung safe areas

apps/web/app/(dashboard)/contribuyentes/addons-dialog.tsx

@@ -67,7 +67,7 @@ export function AddonsDialog({
 
   return (
     <Dialog open={!!target} onOpenChange={(o) => !o && onClose()}>
-      <DialogContent className="max-w-2xl">
+      <DialogContent className="max-w-[95vw] md:max-w-2xl">
         <DialogHeader>
           <DialogTitle className="flex items-center gap-2"><Sparkles className="h-5 w-5 text-amber-500" /> Add-ons — {target?.nombre}</DialogTitle>
         </DialogHeader>