Merge-time fix for #659.
- Alt+Left/Right (File Viewer back/forward) is a display-only entry in
DEFAULT_SHORTCUTS, so the Ctrl+? overlay lists it, and a row in the
help modal's Panels group, pinned in help-modal-shortcuts.test.ts.
zh-CN entry for the new label; the "Restore size" entry is dropped,
since nothing shows that string any more.
- The wiki row moves from "Sessions and tabs" to "Everything else".
- The grip comment in styles.css says only phones hide the grip;
tablets show and use it.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>