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/components/membership-switcher.tsx

@@ -65,10 +65,10 @@ export function MembershipSwitcher() {
       <button
         onClick={() => setOpen(!open)}
         disabled={switching}
-        className="flex items-center gap-2 rounded-lg px-3 py-2 text-sm font-medium hover:bg-accent transition-colors disabled:opacity-50"
+        className="flex items-center gap-2 rounded-lg px-2 py-2 text-sm font-medium hover:bg-accent transition-colors disabled:opacity-50 sm:px-3"
       >
         <Building2 className="h-4 w-4" />
-        <span className="max-w-[180px] truncate">
+        <span className="hidden max-w-[180px] truncate sm:inline">
           {activeTenant?.nombre || user?.tenantName}
         </span>
         {switching