- devdesk attach --fs-list/--fs-read/--git-status/--git-show/--asset (libexec/devdesk-files.sh), confined to the session folder. - The state hook records files Claude edits (Edit/Write/MultiEdit/ NotebookEdit) for the Changes tab's "C" badge; rename/end carry it. - Files pane: folders, CodeMirror read-only view, sanitized markdown preview in a sandboxed iframe with inlined relative images, images, Changes tab with line counts and diff against HEAD, "→ Claude" @path, resizable split. - The editor bundle ships as /usr/share/devdesk/assets/editor.js, is fetched over ttyd on first use, verified against the page's SHA-256 and cached in IndexedDB. - Fix: the state hook's field split collapsed empty fields. Closes #19 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>