rlmesh_remote_env_render_mode
Env construction connects; Model construction only validates. Remote I/O is exclusive, while immutable accessors/cancellation may overlap any call. Accessor pointers remain borrowed until free, including after close.
RLMeshStatus rlmesh_remote_env_render_mode(
const RLMeshRemoteEnv* remote_env,
bool* out_has,
RLMeshBytes* out
)