feat: add unique license number check for devices

shop/lib/actions/queries.ts

@@ -260,4 +260,29 @@ export async function getCustomersForWizard(
   }
 }
 
+/**
+ * Checks if a license number is already taken by any active order.
+ */
+export async function isLicenseNumberTaken(licenseNumber: string, excludeOrderId?: string): Promise<boolean> {
+  const normalized = licenseNumber?.trim().toUpperCase()
+  if (!normalized) return false
+
+  const supabase = await createClient()
+  let query = supabase
+    .from('orders')
+    .select('id')
+    .contains('order_snapshot', { items: [{ license_number: normalized }] })
+
+  if (excludeOrderId) {
+    query = query.neq('id', excludeOrderId)
+  }
+
+  const { data, error } = await query
+  if (error) {
+    console.error('Error checking license number:', error)
+    return false
+  }
+  return !!(data && data.length > 0)
+}
+