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.md

@@ -6,15 +6,15 @@ domain: ui
 version: "1.0.0"
 purity: impure
 signature: "ChartContainer(props: { children: ReactNode; height?: number | string }): JSX.Element"
-description: "Base para todos los charts Recharts: container responsive, tooltip temático, legend y utilidades de colores por serie."
-tags: [chart, container, recharts, base, visualization, component, ui]
-uses_functions: [cn_ts_core, get_series_color_ts_core]
+description: "Thin wrapper Paper y utilidades de colores/series para los charts @mantine/charts."
+tags: [chart, container, mantine, base, visualization, component, ui]
+uses_functions: []
 uses_types: [ChartSeries_ts_ui]
 returns: []
 returns_optional: false
 error_type: ""
-imports: [recharts, react]
-output: "Componente ChartContainer que renderiza base responsive para gráficos Recharts con tooltip y legend temáticos"
+imports: ["@mantine/core"]
+output: "Componente ChartContainer Paper wrapper y utilidades getSeriesColor/Series para charts Mantine"
 tested: false
 tests: []
 test_file_path: ""
@@ -40,11 +40,13 @@ source_file: "frontend/src/components/ui/charts/chart-base.tsx"
 ## Ejemplo
 
 ```tsx
+import { ChartContainer, getSeriesColor, type Series } from './chart_container'
+
 <ChartContainer height={400}>
-  <RechartsLineChart data={data}>...</RechartsLineChart>
+  <MantineLineChart ... />
 </ChartContainer>
 ```
 
 ## Notas
 
-Exporta: ChartContainer, ChartTooltipContent, ChartTooltip, ChartLegend, chartColors, defaultColors, getSeriesColor, Series.
+Exporta: ChartContainer, defaultColors, getSeriesColor, Series. Wrapper fino sobre Mantine Paper para layout uniforme de charts.