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.

dankclaw/apply_qwen21_patch.py

@@ -0,0 +1,34 @@
+import os
+
+# Apply qwen_image21 detection patch
+f = "/opt/ComfyUI/comfy/model_detection.py"
+with open(f) as fh:
+    code = fh.read()
+if "qwen_image21" not in code:
+    qwen21_check = (
+        "    if '{}txt_in.text_norm.weight'.format(key_prefix) in state_dict_keys:  # Qwen Image 2.1\n"
+        "        dit_config = {}\n"
+        '        dit_config["image_model"] = "qwen_image21"\n'
+        "        dit_config[\"in_channels\"] = state_dict['{}img_in.weight'.format(key_prefix)].shape[1]\n"
+        "        dit_config[\"num_layers\"] = count_blocks(state_dict_keys, '{}transformer_blocks.'.format(key_prefix) + '{}.')\n"
+        "        return dit_config\n"
+    )
+    anchor = "    if '{}txt_norm.weight'.format(key_prefix) in state_dict_keys:  # Qwen Image"
+    code = code.replace(anchor, qwen21_check + "\n" + anchor)
+    with open(f, "w") as fh:
+        fh.write(code)
+    print("Applied qwen_image21 detection patch")
+
+# Add qwen_image21 to GGUF node arch list
+loader = "/opt/ComfyUI/custom_nodes/ComfyUI-GGUF/loader.py"
+if os.path.exists(loader):
+    with open(loader) as fh:
+        lcode = fh.read()
+    if '"qwen_image21"' not in lcode:
+        old = '"lumina2", "qwen_image"}'
+        new = '"lumina2", "qwen_image", "qwen_image21"}'
+        if old in lcode:
+            lcode = lcode.replace(old, new)
+            with open(loader, "w") as fh:
+                fh.write(lcode)
+            print("Applied qwen_image21 arch list patch")