initial: mirror of @fn_library from fn_registry

75 components + DESIGN_SYSTEM.md + sync script.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

components/checkbox.md

@@ -0,0 +1,73 @@
+---
+name: checkbox
+kind: component
+lang: ts
+domain: ui
+version: "1.0.0"
+purity: impure
+signature: "Checkbox(props: CheckboxProps): JSX.Element"
+description: "Input booleano accesible con label opcional y variante indeterminate. Mantine Checkbox."
+tags: [checkbox, component, ui, interactive, form, mantine]
+uses_functions: []
+uses_types: []
+returns: []
+returns_optional: false
+error_type: ""
+imports: ["@mantine/core"]
+output: "Componente Checkbox que renderiza input booleano accesible con label opcional y estado indeterminate"
+tested: false
+tests: []
+test_file_path: ""
+file_path: "frontend/functions/ui/checkbox.tsx"
+props:
+  - name: label
+    type: "string"
+    required: false
+    description: "Texto de etiqueta visible junto al checkbox"
+  - name: indeterminate
+    type: "boolean"
+    required: false
+    description: "Estado indeterminate (guion) en vez de checked/unchecked"
+  - name: checked
+    type: "boolean"
+    required: false
+    description: "Estado controlado del checkbox"
+  - name: defaultChecked
+    type: "boolean"
+    required: false
+    description: "Estado inicial no controlado"
+  - name: disabled
+    type: "boolean"
+    required: false
+    description: "Deshabilita el checkbox"
+  - name: onCheckedChange
+    type: "(checked: boolean) => void"
+    required: false
+    description: "Callback cuando cambia el estado"
+emits: [onCheckedChange]
+has_state: false
+framework: react
+variant: []
+---
+
+## Ejemplo
+
+```tsx
+// Basico
+<Checkbox label="Acepto los terminos" />
+
+// Controlado
+<Checkbox
+  label="Seleccionar todos"
+  checked={allSelected}
+  indeterminate={someSelected}
+  onCheckedChange={setAllSelected}
+/>
+
+// Sin label
+<Checkbox checked={isActive} onCheckedChange={setIsActive} />
+```
+
+## Notas
+
+Usa Mantine Checkbox para accesibilidad completa (keyboard, ARIA). El estado indeterminate se muestra con un guion horizontal. El callback onCheckedChange se adapta desde el onChange nativo de Mantine.