Revert "fix(sync): handle close trades without matching open position"

This reverts commit 9c57134dfb.

store/position.go

@@ -253,33 +253,6 @@ func (s *PositionStore) ClosePositionFully(id int64, exitPrice float64, exitOrde
 	}).Error
 }
 
-// GetSyntheticClosedPosition gets an existing synthetic CLOSED position (close_reason='sync_partial')
-// Used when merging multiple close trades that have no matching open position
-func (s *PositionStore) GetSyntheticClosedPosition(traderID, symbol, side string) (*TraderPosition, error) {
-	var pos TraderPosition
-	err := s.db.Where("trader_id = ? AND symbol = ? AND side = ? AND status = ? AND close_reason = ?",
-		traderID, symbol, side, "CLOSED", "sync_partial").
-		Order("exit_time DESC").
-		First(&pos).Error
-	if err != nil {
-		return nil, err
-	}
-	return &pos, nil
-}
-
-// UpdateSyntheticPosition updates a synthetic CLOSED position with additional close trade data
-func (s *PositionStore) UpdateSyntheticPosition(id int64, entryQty, exitPrice, realizedPnL, fee float64, exitTimeMs int64) error {
-	nowMs := time.Now().UTC().UnixMilli()
-	return s.db.Model(&TraderPosition{}).Where("id = ?", id).Updates(map[string]interface{}{
-		"entry_quantity": entryQty,
-		"exit_price":     exitPrice,
-		"realized_pnl":   realizedPnL,
-		"fee":            fee,
-		"exit_time":      exitTimeMs,
-		"updated_at":     nowMs,
-	}).Error
-}
-
 // DeleteAllOpenPositions deletes all OPEN positions for a trader
 func (s *PositionStore) DeleteAllOpenPositions(traderID string) error {
 	return s.db.Where("trader_id = ? AND status = ?", traderID, "OPEN").Delete(&TraderPosition{}).Error