fix(responsive): layout 100% width en todas las resoluciones

- Eliminado max-w-[1280px] de todas las apps (mi-dia, landing, cotizador, cobranza, dashboards, alta-clientes)
- Kanban: sin restricción de ancho, columnas min-w-[220px]
- Grids: xl:grid-cols-4/5 para pantallas grandes
- CSS base: -webkit-text-size-adjust + min-h-screen
- 6 apps construidas

apps/landing/src/components/Navbar.tsx

@@ -27,7 +27,7 @@ export function Navbar({ usuario, onConfiguraciones }: Props) {
 
   return (
     <header className="sticky top-0 z-10 border-b border-[#E5E7EB] bg-white/95 backdrop-blur dark:border-[#1E293B] dark:bg-[#1E293B]/95">
-      <div className="mx-auto flex h-14 max-w-[1280px] items-center justify-between px-4 sm:px-6">
+      <div className="flex h-14 items-center justify-between px-4 sm:px-6 lg:px-8">
         <span className="text-base font-semibold tracking-tight text-[#111827] dark:text-[#E2E8F0]">
           FRASA<span className="text-accent">.</span>
         </span>

apps/landing/src/components/VistaContactos.tsx

@@ -69,7 +69,7 @@ export function VistaContactos({ onVolver }: Props) {
   useEffect(() => cargar(), [cargar])
 
   return (
-    <main className="mx-auto w-full max-w-[1280px] flex-1 px-4 py-12 sm:px-6 sm:py-16">
+    <main className="w-full flex-1 px-4 py-12 sm:px-6 lg:px-8 sm:py-16">
       <div className="flex items-center gap-4">
         <button
           type="button"

apps/landing/src/components/config/ConfigPage.tsx

@@ -25,7 +25,7 @@ export function ConfigPage({ onVolver }: Props) {
   const tabs = esAdmin ? [...TABS_BASE, { key: 'auditoria' as const, label: 'Auditoría' }] : TABS_BASE
 
   return (
-    <main className="mx-auto w-full max-w-[1280px] flex-1 px-6 py-12 sm:py-16">
+    <main className="w-full flex-1 px-6 py-12 sm:px-6 lg:px-8 sm:py-16">
       <div className="flex items-center gap-4">
         <button
           type="button"