rlmesh_frame_sources_render
Session-made sources retain weak state: render after session free returns ERR_RUNTIME. Context-made sources retain the context. Facade closed/busy/ dispatch checks remain in force, including after a C callback transfers sources.
RLMeshStatus rlmesh_frame_sources_render(
const RLMeshFrameSources* frame_sources,
RLMeshValue** out,
bool* out_has
)