fix(comfyui): add missing launch command, drop dead PUID/PGID vars

yurisasc/comfyui-rocm7.1 has no entrypoint/CMD of its own (drops into
bash) and never reads PUID/PGID/VIDEO_GID/RENDER_GID/BASE_STORAGE_PATH
- confirmed by inspecting the image directly. Without an explicit
command the container just exits 0 immediately and restart-loops
forever with zero log output, which is what was actually blocking
comfyui.home/8138, unrelated to the earlier GGUF model swap.

Add `command: python main.py --listen 0.0.0.0 --port 8188
--base-directory /storage` (the real way to point it at the storage
volume) and remove COMFYUI_PUID/COMFYUI_PGID, since nothing consumes
them.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.env.example

@@ -101,12 +101,6 @@ OMNIROUTE_WS_BRIDGE_SECRET=
 # as you onboard one. See docs/proxy-key-onboarding.md.
 
 # --- ComfyUI (local image generation, see issue #38 wayfinder map) ---
-# yurisasc/comfyui-rocm7.1 manages GPU-group access via these GID/UID env
-# vars rather than relying solely on docker-compose.yml's group_add.
-# Resolved automatically from the host by ./scripts/update.sh — leave blank.
-COMFYUI_PUID=
-COMFYUI_PGID=
-
 # Shared by every GPU-touching service (llama-server, llama-server-fast,
 # comfyui) for group_add: — resolved to real host GIDs by ./scripts/update.sh
 # rather than left as plain group names in docker-compose.yml, because Docker