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/chart_container.tsx

@@ -1,14 +1,4 @@
-import * as React from 'react'
-import { cn } from '../core/cn'
-import { ResponsiveContainer, Tooltip as RechartsTooltip, Legend as RechartsLegend } from 'recharts'
-
-export const chartColors = [
-  'hsl(var(--chart-1, 220 70% 50%))',
-  'hsl(var(--chart-2, 160 60% 45%))',
-  'hsl(var(--chart-3, 30 80% 55%))',
-  'hsl(var(--chart-4, 280 65% 60%))',
-  'hsl(var(--chart-5, 340 75% 55%))',
-]
+import { Paper } from '@mantine/core'
 
 export const defaultColors = ['#3b82f6', '#22c55e', '#f59e0b', '#8b5cf6', '#ec4899']
 
@@ -19,62 +9,25 @@ export interface Series {
 }
 
 export function getSeriesColor(index: number, color?: string): string {
-  return color || defaultColors[index % defaultColors.length]
+  return color || defaultColors[index % defaultColors.length]!
 }
 
 interface ChartContainerProps {
   children: React.ReactNode
-  className?: string
   height?: number | string
 }
 
-export function ChartContainer({ children, className, height = 300 }: ChartContainerProps) {
+export function ChartContainer({ children, height = 300 }: ChartContainerProps) {
   return (
-    <div
-      className={cn('w-full', className)}
-      style={{ height, minWidth: 100, minHeight: typeof height === 'number' ? Math.min(height, 100) : 100 }}
-    >
-      <ResponsiveContainer width="100%" height="100%">
-        {children as React.ReactElement}
-      </ResponsiveContainer>
-    </div>
+    <Paper p="md" style={{ height, minWidth: 100, minHeight: typeof height === 'number' ? Math.min(height, 100) : 100 }}>
+      {children}
+    </Paper>
   )
 }
 
-interface ChartTooltipContentProps {
-  active?: boolean
-  payload?: Array<{ name: string; value: number; color: string; dataKey: string }>
-  label?: string
-  labelFormatter?: (label: string) => string
-  valueFormatter?: (value: number) => string
-}
-
-export function ChartTooltipContent({
-  active, payload, label,
-  labelFormatter = (l) => l,
-  valueFormatter = (v) => v.toLocaleString(),
-}: ChartTooltipContentProps) {
-  if (!active || !payload?.length) return null
-  return (
-    <div className="rounded-lg border bg-background p-2 shadow-md">
-      <p className="mb-1 text-sm font-medium">{labelFormatter(label || '')}</p>
-      <div className="space-y-0.5">
-        {payload.map((entry, index) => (
-          <div key={index} className="flex items-center gap-2 text-sm">
-            <div className="size-2.5 rounded-full" style={{ backgroundColor: entry.color }} />
-            <span className="text-muted-foreground">{entry.name}:</span>
-            <span className="font-medium">{valueFormatter(entry.value)}</span>
-          </div>
-        ))}
-      </div>
-    </div>
-  )
-}
-
-export function ChartTooltip(props: React.ComponentProps<typeof RechartsTooltip>) {
-  return <RechartsTooltip content={<ChartTooltipContent />} cursor={{ fill: 'hsl(var(--muted) / 0.3)' }} {...props} />
-}
-
-export function ChartLegend(props: React.ComponentProps<typeof RechartsLegend>) {
-  return <RechartsLegend wrapperStyle={{ paddingTop: 16 }} {...props} />
-}
+/** @deprecated Mantine charts handle tooltips internally. Kept for index.ts compat. */
+export function ChartTooltipContent() { return null }
+/** @deprecated Mantine charts handle tooltips internally. Kept for index.ts compat. */
+export function ChartTooltip() { return null }
+/** @deprecated Mantine charts handle legends internally. Kept for index.ts compat. */
+export function ChartLegend() { return null }