feat(comfyui): native --use-sage-attention (node path dead on 0.24.1)

ComfyUI 0.24.1 added native attention selection; the node-based
BlehGlobalSageAttention errors "does not support the new ComfyUI attention
changes". Add --use-sage-attention to COMFY_CMDLINE_EXTRA so the in-image
sageattention v2.2.0 sm_86 build (rebuilt vs pinned torch 2.12.1) binds via
the native path. OOM flags preserved. Deployed to irv-ml1 + recreated; log
confirms "Using sage attention", container healthy, serving 200.
(comfy-dev request, thread 01KVE89T2DKC)

stacks/comfyui/compose.yaml

@@ -51,7 +51,12 @@ services:
       #    (~8.7 GB) instead of upcasting the fp8 file to fp16 (~16 GB). Matches
       #    the box's Ampere-fp8 posture; the encoder runs once per gen so the
       #    upcast-on-compute cost is negligible.
-      - COMFY_CMDLINE_EXTRA=--disable-cuda-malloc --fp8_e4m3fn-text-enc
+      #  --use-sage-attention — 0.24.1's NATIVE attention selection (the node-based
+      #    BlehGlobalSageAttention is dead on 0.24.1: "does not support the new
+      #    ComfyUI attention changes"). Binds the in-image sageattention v2.2.0
+      #    sm_86 build (rebuilt against the pinned torch 2.12.1). Global speedup
+      #    across Flux/SDXL/Wan (comfy-dev benchmarking, 2026-06-18).
+      - COMFY_CMDLINE_EXTRA=--disable-cuda-malloc --fp8_e4m3fn-text-enc --use-sage-attention
     volumes:
       - ${COMFYUI_BASEDIR}:/basedir
       # models/ overlaid from storetank. The ~325 GB model tree was migrated