feat(loyalty): remove paying with EnakPoint

EnakPoint can only be redeemed for vouchers now: it can no longer pay for
orders and is never cashed out (docs/enakgame-prd.md §3.2, EG-001,
EG-002). No order was ever paid with EnakPoint, so there is no data to
move.

Removed:
- POST /customer/wallet/payment-code, POST /customer/orders/:id/pay-with-points
  and GET /orders/:id/point-payment/preview, with their processors,
  repositories, services, handlers and tests.
- The point payment method type: paying, splitting and refunding with it,
  the outlet filter on the method list, and the system-method guard.
- points and payment_code on CreatePayment; points_used and point_value
  on payments; accepts_point_payment on the customer outlets.
- The outlet point_payment settings. A PUT that still sends them is
  rejected as an unknown field.
- The EnakPoint split in the payment method analytics.
- PAYMENT and PAYMENT_REFUND from the wallet type rules. Tests that used
  them as a generic EnakPoint debit use REWARD_REDEEM.
- The EnakPoint-paid part from the earning basis, which is
  subtotal − discount again.

Migration 000102 drops the trigger, the point methods and their index,
the payments columns, and the outlet settings, and restores the method
type CHECK without point. payments.payment_method_id is ON DELETE
RESTRICT, so it fails rather than lose a payment made with EnakPoint.

The integration docs list the removed endpoints and fields, and the
EnakPoint & EnakCoin PRD and tasks note what is superseded.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/models/wallet.go

@@ -139,25 +139,6 @@ type AdminWalletAdjustmentResult struct {
 	Replayed bool `json:"replayed"`
 }
 
-// PointPaymentPreview is GET /orders/:id/point-payment/preview (docs/prd-point-coin.md
-// F9): whether the order can be paid with EnakPoint and at most how much, for the
-// cashier's "use maximum" button.
-type PointPaymentPreview struct {
-	OrderID    uuid.UUID  `json:"order_id"`
-	CustomerID *uuid.UUID `json:"customer_id"`
-	Eligible   bool       `json:"eligible"`
-	// Why not, when not eligible.
-	Reason            string  `json:"reason,omitempty"`
-	PointBalance      int64   `json:"point_balance"`
-	PointValue        int64   `json:"point_value"`
-	RemainingAmount   float64 `json:"remaining_amount"`
-	MinPaymentPoints  int64   `json:"min_payment_points"`
-	MaxPaymentPercent int64   `json:"max_payment_percent"`
-	MaxPoints         int64   `json:"max_points"`
-	// Rupiah covered by MaxPoints.
-	MaxAmount int64 `json:"max_amount"`
-}
-
 // CustomerWalletExpiringList is GET /customer/wallet/expiring (docs/prd-point-coin.md
 // F6): everything that will expire, per currency and day, soonest first.
 type CustomerWalletExpiringList struct {