Normalize RUC formatting to base-checkdigit across booking and admin views.

Accept dashed or digits-only RUC input on the backend, store a canonical dashed form, and display it consistently in booking and admin UIs.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/lib/utils.ts

@@ -166,6 +166,18 @@ export function formatCurrency(amount: number, currency: string = 'PYG'): string
   return formatPrice(amount, currency);
 }
 
+/**
+ * Format a Paraguayan RUC for display as "base-checkdigit" (e.g. 1234567-9).
+ * Legacy records stored digits only; insert the dash before the check digit.
+ */
+export function formatRucDisplay(ruc: string | null | undefined): string {
+  if (!ruc) return '';
+  if (ruc.includes('-')) return ruc;
+  const digits = ruc.replace(/\D/g, '');
+  if (digits.length < 2) return ruc;
+  return `${digits.slice(0, -1)}-${digits.slice(-1)}`;
+}
+
 // ---------------------------------------------------------------------------
 // Payment helpers
 // ---------------------------------------------------------------------------