refactor: remove yearly billing interval, keep only one_time and monthly

shop/components/admin/create-product-dialog.tsx

@@ -53,7 +53,7 @@ const productSchema = z.object({
   base_price: z.coerce.number().min(0, 'Preis darf nicht negativ sein'),
   category_id: z.string().min(1, 'Bitte wählen Sie eine Kategorie'),
   is_active: z.boolean().default(true),
-  billing_interval: z.enum(['one_time', 'monthly', 'yearly']).default('monthly'),
+  billing_interval: z.enum(['one_time', 'monthly']).default('monthly'),
   modules: z.array(moduleSchema).default([]),
 })
 
@@ -190,11 +190,10 @@ export function CreateProductDialog({ children, categories, product }: { childre
                   render={({ field }) => (
                     <FormItem>
                       <FormLabel className="text-white">Abrechnungsmodell</FormLabel>
-                      <div className="grid grid-cols-3 gap-2 pt-1">
+                      <div className="grid grid-cols-2 gap-2 pt-1">
                         {[
                           { value: 'one_time', label: 'Einmalig',  icon: '💳' },
                           { value: 'monthly',  label: 'Monatlich', icon: '🔄' },
-                          { value: 'yearly',   label: 'Jährlich',  icon: '📅' },
                         ].map(opt => (
                           <button
                             key={opt.value}