The presets move from app.js to presets.json, built into the binary and
served by /api/presets. PRESETS_FILE (default /data/presets.json) replaces
the list when present; it is read again each time Settings opens and the
built-in list is used if it is invalid. docs/presets.md (EN/FR) explains
each preset and the file format.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
