优化结构

internal/service/system/export_excel_value_test.go

@@ -8,3 +8,9 @@ func TestExportCellValuePreservesNumericText(t *testing.T) {
 		t.Fatalf("exportCellValue() = %#v, want string 007", exportCellValue("007"))
 	}
 }
+
+func TestExportCellValuePreservesDriverBytes(t *testing.T) {
+	if value, ok := exportCellValue([]byte("42")).(string); !ok || value != "42" {
+		t.Fatalf("driver bytes = %#v", exportCellValue([]byte("42")))
+	}
+}