fix: move withdrawal commission deduction from application to approval

- commissionWithdrawLogic: remove upfront commission deduction;
  balance check now includes sum of all pending withdrawals to prevent
  double-spending; transaction only creates the withdrawal record (status=0)
- approveWithdrawal: add FOR UPDATE lock on user row, balance check before
  deducting, atomic commission decrement and commission log inside one
  transaction; clear user cache after commit
- rejectWithdrawal: remove commission refund and log — commission was never
  deducted on application under the new flow
- add migration 02150: refund commission for existing status=0 withdrawals
  that were deducted under the old logic; includes rollback script

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

internal/logic/common/withdrawal.go

@@ -0,0 +1,48 @@
+package common
+
+import (
+	"context"
+	"time"
+
+	"github.com/perfect-panel/server/internal/model/log"
+	usermodel "github.com/perfect-panel/server/internal/model/user"
+	"github.com/pkg/errors"
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+func WriteCommissionLog(tx *gorm.DB, objectID int64, logType uint16, amount int64, orderNo string) error {
+	logInfo := log.Commission{
+		Type:      logType,
+		Amount:    amount,
+		OrderNo:   orderNo,
+		Timestamp: time.Now().UnixMilli(),
+	}
+
+	content, err := logInfo.Marshal()
+	if err != nil {
+		return err
+	}
+
+	return tx.Model(log.SystemLog{}).Create(&log.SystemLog{
+		Type:      log.TypeCommission.Uint8(),
+		Date:      time.Now().Format(time.DateOnly),
+		ObjectID:  objectID,
+		Content:   string(content),
+		CreatedAt: time.Now(),
+	}).Error
+}
+
+func LoadPendingWithdrawalForUpdate(ctx context.Context, tx *gorm.DB, withdrawalID int64) (*usermodel.Withdrawal, error) {
+	var withdrawal usermodel.Withdrawal
+	if err := tx.WithContext(ctx).
+		Clauses(clause.Locking{Strength: "UPDATE"}).
+		Where("id = ?", withdrawalID).
+		First(&withdrawal).Error; err != nil {
+		return nil, err
+	}
+	if withdrawal.Status != 0 {
+		return nil, errors.New("withdrawal status invalid")
+	}
+	return &withdrawal, nil
+}