fix: close platform admin final audit findings

backend/api/internal/models/wallet_withdrawal.go

@@ -4,10 +4,10 @@ import "git.apinb.com/bsm-sdk/core/database"
 
 // WalletWithdrawal 对应 wallet_withdrawal，保存提现记录。
 type WalletWithdrawal struct {
-	Entity
-	WalletID          uint64 `gorm:"column:wallet_id;not null;index" json:"wallet_id"`
-	Amount            int64  `gorm:"column:amount;not null" json:"amount"`
-	BankAccountMasked string `gorm:"column:bank_account_masked;type:varchar(128);not null;default:''" json:"bank_account_masked"`
+	Entity                   // 公共实体字段
+	WalletID          uint64 `gorm:"column:wallet_id;not null;index" json:"wallet_id"`                                            // wallet_id 业务字段
+	Amount            int64  `gorm:"column:amount;not null" json:"amount"`                                                        // amount 业务字段
+	BankAccountMasked string `gorm:"column:bank_account_masked;type:varchar(128);not null;default:''" json:"bank_account_masked"` // bank_account_masked 业务字段
 }
 
 func init()                                       { database.AppendMigrate(&WalletWithdrawal{}) }