rlmesh_env_server_new_vector
New binds. start runs callbacks on library threads; serve keeps lane 0 on the caller. shutdown is allowed from a callback. Free shuts down and drains all C callbacks, including any still running past the facade's timeout.
RLMeshStatus rlmesh_env_server_new_vector(
RLMeshVectorEnv* vector_env,
const RLMeshEnvServerOptions* options,
RLMeshEnvServer** out
)