comfyui: bake qwen_image21 patch into image via startup wrapper

The qwen_image21 detection check and GGUF node arch list patch are
applied by a startup wrapper (comfyui-start.sh) that runs before
ComfyUI starts. The patch script and wrapper are baked into the image
so they survive container recreations. The quadlet's Exec now points
at the wrapper instead of main.py directly.

tests/comfyui_rocm.bats

@@ -68,12 +68,19 @@ load helpers
 
 @test "comfyui does not run with --cpu" {
     local unit="$REPO_ROOT/dankclaw/comfyui/quadlet/comfyui.container"
+    local wrapper="$REPO_ROOT/dankclaw/comfyui-start.sh"
     local exec_line
     exec_line=$(grep -E '^Exec=' "$unit")
+    # The exec line points at the startup wrapper; the actual flags live there.
+    local target
     case "$exec_line" in
+        *comfyui-start.sh*) target="$wrapper" ;;
+        *) target="$unit" ;;
+    esac
+    case "$(grep -E 'main\.py|--cpu' "$target")" in
         *--cpu*) echo "comfyui must not pass --cpu (ROCm GPU build)"; return 1 ;;
     esac
-    case "$exec_line" in
+    case "$(grep -E 'main\.py|--listen' "$target")" in
         *--listen*) ;;
         *) echo "comfyui must listen on 0.0.0.0"; return 1 ;;
     esac