Confine local file installation paths

internal/fileops/sync_directory_unsupported.go

@@ -4,9 +4,14 @@ package fileops
 
 import (
 	"fmt"
+	"os"
 	"runtime"
 )
 
 func syncDirectory(path string) error {
 	return fmt.Errorf("%w for %q on %s", ErrDirectorySyncUnsupported, path, runtime.GOOS)
 }
+
+func syncDirectoryFile(_ *os.File, path string) error {
+	return syncDirectory(path)
+}