Link @libepoxy (or @libepoxy//:epoxy) for the native Linux GL, GLX, and EGL dispatch library. Upstream gen_dispatch.py generates dispatch sources from the release's Khronos XML files on the execution platform. No installed GL headers or libraries are needed at build time. GPU drivers are loaded with dlopen at runtime; linking this library statically does not embed a driver. The smoke test links all three public dispatch APIs without opening a display.