rlmesh_model_describe
NULL options means INIT. Type forms call no vtable slot. Instance forms use the facade's static declarations and model spec/representative factory builds. The Value result is an owned Dict, JSON is owned RLMeshBytes. served_env NULL/0 = None; non-NULL/0 is an invalid empty list. At most one served form may be set. It replaces the default build and is never closed. workflow_edition NULL resolves/records refusal; "" explicitly declares none.
RLMeshStatus rlmesh_model_describe(
const RLMeshModel* model,
const RLMeshDescribeOptions* options,
RLMeshValue** out
)