nx_session_real_llm_compose_test.nx

nx_session_real_llm_compose_test.nx -- demonstrates how nx_session + nx_gguf_fixture_tiny + nx_actor_role_llm_v2 compose into a tight real-transformer scene. Previous compose smokes (nx_companion_compose, dual/triple/quad) each had 30+ lines of wiring boilerplate to set up the scheduler + bus + multiplexer + arbiter + broker + actor + register + subscribe. This smoke shows the new composite path: ~10 lines of substrate setup, then real-transformer-forward through the actor, then drain. The COMPOSED primitives do the work.