Flatpak opens only /usr/share/fonts and ~/.local/share/fonts to a sandbox, so the
fonts a font manager such as FontBase activates into ~/.fonts were missing from the
font list while native apps showed them. Granted read-only: VectorCraft only reads
fonts.
Verified on the 0.11.0 release bundle by applying the same grant as a user override
(`flatpak override --user --filesystem=~/.fonts:ro`): in a fresh sandbox the FontBase
families went from none to all 167, `fc-match` resolved a family that had been missing
from the app, and the font then appeared in the font list.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
