fix: size 0 bug

fix: huge index can't sort _id, back use scroll_id
refac: some files arch

internal/interfaces/dumpio.go

@@ -2,11 +2,12 @@ package interfaces
 
 import (
 	"context"
+
 	"github.com/loveuer/esgo2dump/model"
 )
 
 type DumpIO interface {
-	ReadData(ctx context.Context, size uint64, query map[string]any, includeFields []string, sort []string) (<-chan []*model.ESSource, <-chan error)
+	ReadData(ctx context.Context, size int, query map[string]any, includeFields []string, sort []string) (<-chan []*model.ESSource, <-chan error)
 	WriteData(ctx context.Context, docsCh <-chan []*model.ESSource) error
 
 	ReadMapping(context.Context) (map[string]any, error)