Align directory indicator style with ncdu convention

[ScottMorris]

Summary

The file list entry format differs from ncdu's convention in how directory indicators are displayed.

ncdu style: /dirname — slash directly attached to the name, no trailing slash

  12.8 MiB [########  ] /jiti
  23.0 MiB [##########]  tmp-csn.xpi

smdu style: / dirname/ — space between indicator and name, plus trailing slash

/ lib/
  .updated

The extra space between the / indicator and the name, combined with the trailing /, makes directory entries slightly harder to scan visually.

Location

src/components/FileList.tsx line 330:

const entryLabel = `${indent}${file.isDirectory ? '/' : ' '} ${sanitize(displayName)}`;

Considerations

• Remove the space between indicator and name to match ncdu: /dirname
• Decide whether to keep trailing / (redundant with leading indicator) or drop it
• Ensure tree mode indentation still looks correct with the tighter format