Package-level declarations

Opens independent CPU font backends without Minecraft, a window, or a graphics context. The application supplies the target release's LWJGL bindings, native classifiers, and ICU version on its runtime classpath. This immutable factory owns no native state and is safe to share; every opened backend is confined to its opening thread. Different LWJGL native generations must run in separate processes. Opening or using a backend fails when required bindings or native libraries are absent; no operating-system font fallback is used.