docs(comfyui): the GTT aperture is not free RAM beside frank-dragoon

Measured 2026-10-21 with frank-dragoon live: MemAvailable 15.3 GiB,
iGPU busy 1.75 GiB. The Qwen-Image weight sets (13.3-14.2 GB) do not
fit that budget, and the page's 122 GB /system_stats figure is the
aperture, not headroom. Adds the fit table and the
stop-mask-render-verify procedure (the 3090 bench law, applied to the
APU); ComfyUI.md gotcha links it.

serverAppConfigs-docs/Dankclaw/ComfyUI.md

@@ -129,6 +129,12 @@ bind-mounted to `/usr/local/bin/comfyui-healthcheck.py` and run as `HealthCmd`
 - Do not let pip reinstall the torch family. The Containerfile filters it out on purpose.
 - The base image is about 32 GiB (`podman image inspect localhost/comfyui-rocm:gfx1151` → 33,765,227,471 B ≈ 31.4 GiB, 2026-10-18). A code update means a rebuild, because the code is baked in.
 - The empty-models note from the 2026-09-16 era is retired: `/home/dank/comfyui-data/models` now holds the Qwen-Image 2.1 payload — three `diffusion_models`, three `text_encoders`, two VAEs (~35 GB, `ls -l` 2026-10-18), listed in [[ComfyUI Qwen-Image Workflows]]. New model classes (LoRA, ControlNet) still need their directories created first: `models/lora` and `models/controlnet` do not exist yet.
+- **The 122 GB `/system_stats` VRAM figure is the GTT aperture, not free
+  memory.** On the APU it is system RAM, and frank-dragoon pins most of it
+  (`MemAvailable` 15.3 GiB with the endpoint live, measured 2026-10-21). A
+  Qwen-Image-class render beside the running endpoint is thrash-or-fail; the
+  stop-mask-render-verify procedure and the fit table are in
+  [[ComfyUI Qwen-Image Workflows]] → What actually fits beside frank-dragoon.
 
 ## See Also