refactor: migrate frontend from shadcn/Tailwind to Mantine v9

Reescribe todos los componentes UI para usar Mantine v9 en lugar de shadcn/Tailwind.
Elimina cn(), CVA, components.json, theme_provider custom y globals.css con Tailwind.
Añade 25+ componentes nuevos (AppShell, AuthForm, DatePickerInput, Dropzone, etc.)
y MantineProvider como wrapper estándar del sistema de temas.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/functions/ui/badge.tsx

@@ -1,45 +1,47 @@
-import * as React from "react"
-import { cva, type VariantProps } from "class-variance-authority"
-import { cn } from "../core/cn"
+import * as React from 'react'
+import { Badge as MantineBadge } from '@mantine/core'
 
-const badgeVariants = cva(
-  "group/badge inline-flex h-5 w-fit shrink-0 items-center justify-center gap-1 overflow-hidden rounded-4xl border border-transparent px-2 py-0.5 text-xs font-medium whitespace-nowrap transition-all focus-visible:border-ring focus-visible:ring-[3px] focus-visible:ring-ring/50 [&>svg]:pointer-events-none [&>svg]:size-3!",
-  {
-    variants: {
-      variant: {
-        default: "bg-primary text-primary-foreground [a]:hover:bg-primary/80",
-        secondary: "bg-secondary text-secondary-foreground [a]:hover:bg-secondary/80",
-        destructive: "bg-destructive/10 text-destructive [a]:hover:bg-destructive/20",
-        outline: "border-border text-foreground [a]:hover:bg-muted",
-        ghost: "hover:bg-muted hover:text-muted-foreground dark:hover:bg-muted/50",
-        link: "text-primary underline-offset-4 hover:underline",
-        success: "bg-green-500/10 text-green-600 dark:bg-green-500/20 dark:text-green-400",
-        warning: "bg-yellow-500/10 text-yellow-600 dark:bg-yellow-500/20 dark:text-yellow-400",
-        error: "bg-red-500/10 text-red-600 dark:bg-red-500/20 dark:text-red-400",
-        info: "bg-blue-500/10 text-blue-600 dark:bg-blue-500/20 dark:text-blue-400",
-      },
-      size: {
-        default: "h-5 px-2 text-xs",
-        sm: "h-4 px-1.5 text-[10px]",
-      },
-    },
-    defaultVariants: {
-      variant: "default",
-      size: "default",
-    },
-  }
-)
+type BadgeVariant = 'default' | 'secondary' | 'destructive' | 'outline' | 'ghost' | 'link' | 'success' | 'warning' | 'error' | 'info'
+type BadgeSize = 'default' | 'sm'
 
-interface BadgeProps extends React.HTMLAttributes<HTMLSpanElement>, VariantProps<typeof badgeVariants> {}
+const variantMap: Record<BadgeVariant, { variant: string; color?: string }> = {
+  default: { variant: 'filled' },
+  secondary: { variant: 'light' },
+  destructive: { variant: 'light', color: 'red' },
+  outline: { variant: 'outline' },
+  ghost: { variant: 'subtle' },
+  link: { variant: 'transparent' },
+  success: { variant: 'light', color: 'green' },
+  warning: { variant: 'light', color: 'yellow' },
+  error: { variant: 'light', color: 'red' },
+  info: { variant: 'light', color: 'blue' },
+}
+
+/** Kept for backwards compatibility */
+const badgeVariants = variantMap
+
+interface BadgeProps extends React.HTMLAttributes<HTMLDivElement> {
+  variant?: BadgeVariant
+  size?: BadgeSize
+}
+
+function Badge({ className, variant = 'default', size = 'default', children, ...props }: BadgeProps) {
+  const mv = variantMap[variant]
 
-function Badge({ className, variant = "default", size = "default", ...props }: BadgeProps) {
   return (
-    <span
+    <MantineBadge
       data-slot="badge"
-      className={cn(badgeVariants({ variant, size }), className)}
+      variant={mv.variant}
+      color={mv.color}
+      size={size === 'sm' ? 'xs' : 'sm'}
+      radius="xl"
+      className={className}
       {...props}
-    />
+    >
+      {children}
+    </MantineBadge>
   )
 }
 
 export { Badge, badgeVariants }
+export type { BadgeProps, BadgeVariant, BadgeSize }