Static MMQ_SK_FORCE 

pub static MMQ_SK_FORCE: AtomicI8

Per-model stream-k override for SPEC serving (-1 = unset → env/default; 0 = force tiling; 1 = force sk). Set by generate_spec_gemma per model tier — the sk autotune’s per-process kernel coin made 12B-class spec cells bimodal, while the 26B’s drafter measures BETTER under sk’s fold order (2026-07-27). mmq_ffi reads this before the env.