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)/calendario/page.tsx

@@ -302,8 +302,9 @@ export default function CalendarioPage() {
             </div>
             <div className="grid grid-cols-7 gap-1">
               {['Dom', 'Lun', 'Mar', 'Mié', 'Jue', 'Vie', 'Sáb'].map(d => (
-                <div key={d} className="text-center text-sm font-medium text-muted-foreground py-2">
-                  {d}
+                <div key={d} className="text-center text-xs md:text-sm font-medium text-muted-foreground py-1 md:py-2">
+                  <span className="md:hidden">{d.charAt(0)}</span>
+                  <span className="hidden md:inline">{d}</span>
                 </div>
               ))}
               {days.map((day, i) => {
@@ -313,14 +314,14 @@ export default function CalendarioPage() {
                   <div
                     key={i}
                     className={cn(
-                      'min-h-[80px] p-1 border rounded-md',
+                      'min-h-[60px] md:min-h-[80px] p-0.5 md:p-1 border rounded-md',
                       day ? 'bg-background' : 'bg-muted/30',
                       isToday && 'ring-2 ring-primary'
                     )}
                   >
                     {day && (
                       <>
-                        <div className={cn('text-sm font-medium', isToday && 'text-primary')}>{day}</div>
+                        <div className={cn('text-xs md:text-sm font-medium', isToday && 'text-primary')}>{day}</div>
                         <div className="space-y-1 mt-1">
                           {dayEventos.slice(0, 2).map((e, idx) => {
                             const Icon = tipoIcons[e.tipo] || Calendar;