Add shared compressed-weight M48 and tail tiles with partial-warp guards. Preserve reference split-K selection, attention reduction trees and rank sum order. Record exact-token ordinary service gains and the remaining C4/C6/C8 performance targets. Assisted-by: OpenAI Codex Signed-off-by: yangzhuxinyzx <153831768+yangzhuxinyzx@users.noreply.github.com>