refactor: remove unused Extractor and Loader interfaces from types.go; streamline code structure

internal/app/etl/types.go

@@ -9,18 +9,6 @@ import (
 	"git.ksdemosapps.com/kylesoda/go-migrate/internal/app/models"
 )
 
-type Extractor interface {
-	ProcessPartition(
-		ctx context.Context,
-		tableInfo config.SourceTableInfo,
-		columns []models.ColumnType,
-		batchSize int,
-		partition models.Partition,
-		indexPrimaryKey int,
-		chBatchesOut chan<- models.Batch,
-	) (int, error)
-}
-
 type TransformerFunc func(any) (any, error)
 
 type ColumnTransformPlan struct {
@@ -40,15 +28,6 @@ type Transformer interface {
 	)
 }
 
-type Loader interface {
-	ProcessBatch(
-		ctx context.Context,
-		tableInfo config.TargetTableInfo,
-		colNames []string,
-		batch models.Batch,
-	) (int64, error)
-}
-
 type TableAnalyzer interface {
 	QueryColumnTypes(
 		ctx context.Context,