fix: remote directory size calculation via SFTP Walk on Space key

internal/fs/remote/client.go

@@ -574,6 +574,24 @@ func (c *SSHClient) walk(dirPath string, walkFn walkFunc, info os.FileInfo) erro
 // filepathSkipDir is used as a return value from Walk to skip a directory.
 var filepathSkipDir = fmt.Errorf("skip this directory")
 
+// DirectorySize recursively walks a remote directory and sums up file sizes.
+func (c *SSHClient) DirectorySize(dirPath string) (int64, error) {
+	var total int64
+	err := c.Walk(dirPath, func(_ string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if !info.IsDir() {
+			total += info.Size()
+		}
+		return nil
+	})
+	if err != nil {
+		return 0, err
+	}
+	return total, nil
+}
+
 // SftpToFileInfo converts an os.FileInfo to a vfs-compatible file info.
 // This is used for consistent file information handling across local and remote.
 func SftpToFileInfo(name string, info os.FileInfo) (os.FileInfo, error) {

internal/ui/model.go

@@ -2325,6 +2325,9 @@ func (m *Model) handleDirSize() (tea.Model, tea.Cmd) {
 	log.Printf("[ACTION] DirSize: path=%s pane=%s", selected.Path, m.active)
 	m.busy = true
 	m.status = fmt.Sprintf("Calculating directory size for %s", selected.DisplayName())
+	if mount, ok := m.activePane().CurrentRemote(); ok {
+		return m, remoteDirSizeCmd(mount.Client, selected.Path)
+	}
 	return m, dirSizeCmd(selected.Path)
 }
 
@@ -4692,6 +4695,13 @@ func dirSizeCmd(path string) tea.Cmd {
 	}
 }
 
+func remoteDirSizeCmd(client *remote.SSHClient, path string) tea.Cmd {
+	return func() tea.Msg {
+		size, err := client.DirectorySize(path)
+		return dirSizeMsg{path: path, size: size, err: err}
+	}
+}
+
 func copyPlanCmd(kind fileOpKind, sourcePaths []string, targetDir string, overwrite bool, existingTargets int) tea.Cmd {
 	return func() tea.Msg {
 		stats := vfs.TransferStats{}