refactor: add reverse configuration and enhance transformation logic for PostgreSQL to SQL Server migration

internal/app/etl/transformers/plan.go

@@ -64,12 +64,28 @@ func computePostgresTransformationPlan(columns []models.ColumnType) []etl.Column
 
 	for i, col := range columns {
 		switch col.SystemType() {
+		case "int2", "int4", "int8", "integer", "smallint", "bigint":
+			plan = append(plan, etl.ColumnTransformPlan{
+				Index: i,
+				Fn: func(v any) (any, error) {
+					if v64, ok := ToInt64(v); ok {
+						return v64, nil
+					}
+					return v, nil
+				},
+			})
+
 		case "uuid":
 			plan = append(plan, etl.ColumnTransformPlan{
 				Index: i,
 				Fn: func(v any) (any, error) {
-					if b, ok := v.([]byte); ok && b != nil {
-						return bigEndianToMssqlUuid(b)
+					switch b := v.(type) {
+					case []byte:
+						if b != nil {
+							return bigEndianToMssqlUuid(b)
+						}
+					case [16]byte:
+						return bigEndianToMssqlUuid(b[:])
 					}
 					return v, nil
 				},