Reapply "feat(loyalty): EnakPoint & EnakCoin" (#32)

This reverts commit 4e24f9bbb0.

internal/handler/payment_method_handler.go

@@ -113,6 +113,16 @@ func (h *PaymentMethodHandler) ListPaymentMethods(c *gin.Context) {
 
 	req.OrganizationID = &contextInfo.OrganizationID
 
+	// At the cashier, EnakPoint is listed only where the outlet accepts it (F9).
+	if outletStr := c.Query("outlet_id"); outletStr != "" {
+		if outletID, err := uuid.Parse(outletStr); err == nil {
+			req.OutletID = &outletID
+		}
+	} else if contextInfo.OutletID != uuid.Nil {
+		outletID := contextInfo.OutletID
+		req.OutletID = &outletID
+	}
+
 	if isActiveStr := c.Query("is_active"); isActiveStr != "" {
 		if isActive, err := strconv.ParseBool(isActiveStr); err == nil {
 			req.IsActive = &isActive