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/tenant-selector.tsx

@@ -53,14 +53,14 @@ export function TenantSelector() {
       <button
         onClick={() => setOpen(!open)}
         className={cn(
-          'flex items-center gap-2 rounded-lg px-3 py-2 text-sm font-medium transition-colors',
+          'flex items-center gap-2 rounded-lg px-2 py-2 text-sm font-medium transition-colors sm:px-3',
           isViewingOther
             ? 'bg-primary/10 text-primary border border-primary/30'
             : 'hover:bg-accent'
         )}
       >
         <Building className="h-4 w-4" />
-        <span className="max-w-[150px] truncate">{displayName}</span>
+        <span className="hidden max-w-[150px] truncate sm:inline">{displayName}</span>
         {isViewingOther && (
           <span
             role="button"