fix: persist guest/redemption activation context to DB to survive Redis TTL expiry (Bug 1 + Bug 10)

- Add `activation_context` TEXT column to `order` table (migration 02150)
- purchaseLogic: write TemporaryOrderInfo JSON to order.ActivationContext in the same
  insert transaction; Redis write is now best-effort (non-fatal)
- redeemCodeLogic: write redemption {type, redemption_code_id, unit_time, quantity} JSON
  to order.ActivationContext at order creation; Redis write is now best-effort (non-fatal)
- getTempOrderInfo: on Redis miss, fall back to order.ActivationContext from DB;
  logs CRITICAL and returns error if both are missing (old orders with no DB record)
- RedemptionActivate: on Redis miss, fall back to order.ActivationContext from DB;
  same CRITICAL log path for legacy orders

Co-authored-by: multica-agent <github@multica.ai>

internal/model/order/order.go

@@ -24,8 +24,9 @@ type Order struct {
 	Status         uint8     `gorm:"type:tinyint(1);not null;default:1;comment:Order Status: 1: Pending, 2: Paid, 3:Close, 4: Failed, 5:Finished;"`
 	SubscribeId    int64     `gorm:"type:bigint;not null;default:0;comment:Subscribe Id"`
 	SubscribeToken  string    `gorm:"type:varchar(255);default:null;comment:Renewal Subscribe Token"`
-	AppAccountToken string    `gorm:"type:varchar(36);default:null;comment:Apple IAP App Account Token (UUID)"`
-	IsNew           bool      `gorm:"type:tinyint(1);not null;default:0;comment:Is New Order"`
+	AppAccountToken   string    `gorm:"type:varchar(36);default:null;comment:Apple IAP App Account Token (UUID)"`
+	ActivationContext string    `gorm:"type:text;default:null;comment:Activation context JSON (guest/redemption info for DB fallback)"`
+	IsNew             bool      `gorm:"type:tinyint(1);not null;default:0;comment:Is New Order"`
 	CreatedAt      time.Time `gorm:"<-:create;comment:Create Time"`
 	UpdatedAt      time.Time `gorm:"comment:Update Time"`
 }