pub fn kv_cache_formats() -> (&'static str, &'static str)Expand description
KV format policy moved to the shared memra-kv crate (Phase D); re-exported so the
fatbin router below and every existing crate::kv_blk_bytes() call site is unchanged.
Env-selected KV cache formats (MEMRA_KV_K / MEMRA_KV_V). The engine’s flash-fatbin router
and the cache sizing below MUST agree — both read this one function.