feat(comfyui): migrate 325G model tree worktank -> /storetank/arbo

ComfyUI's ~325G model tree moved off the near-full worktank NVMe (97%->26%,
342G free) to /storetank/arbo (roomy SATA SSD on irv-ml1), overlay-mounted
back at /basedir/models so ComfyUI behaviour is unchanged. rsync byte-verified
(src==dst), one comfyui restart, worktank original removed. Inventory of the
set in docs/arbo-comfyui-model-catalog.md for the retain decision. The older
919G /storetank/image-models/comfy archive is untouched (separate reclaim).

stacks/comfyui/compose.yaml

@@ -49,6 +49,12 @@ services:
       - COMFY_CMDLINE_EXTRA=--disable-cuda-malloc --fp8_e4m3fn-text-enc
     volumes:
       - ${COMFYUI_BASEDIR}:/basedir
+      # models/ overlaid from storetank. The ~325 GB model tree was migrated
+      # off the near-full worktank NVMe (2026-06-13) to /storetank/arbo (roomy
+      # SATA SSD). This nested mount shadows the models subdir of /basedir;
+      # everything else (custom_nodes, output, input, user, workflows) stays on
+      # worktank. Inventory: docs/arbo-comfyui-model-catalog.md.
+      - ${COMFYUI_MODELS_DIR:-/storetank/arbo/models}:/basedir/models
       - ${COMFYUI_RUNDIR}:/comfy/mnt
     healthcheck:
       test: ["CMD-SHELL", "curl -fsS http://localhost:8188/ >/dev/null || exit 1"]