fix(spaces): three runtime fixes — input staging dir, walker, cache perms

1. _COMFY_INPUT_DIR was hardcoded to <repo>/comfyui/input — fine locally
but on Spaces ComfyUI lives at ~/comfyui, so user uploads were being
staged to a directory ComfyUI never reads from. Mirror the bootstrap
logic so the staging dir matches comfy_dir on each platform.

2. walk_workflow_for_models() was returning every filename mentioned in
Power Lora Loader rows, including those with on:false. ensure_models
then tried to download those (camera LoRAs) at runtime which failed
noisily and pointlessly. Skip rows whose on flag is falsy.

3. After preload_from_hub bakes ~111 GB into ~/.cache/huggingface/, that
directory tree's permissions can block runtime hf_hub_download writes
(xet log dir, blob targets). chmod -R u+rwX in bootstrap so any model
NOT covered by preload (the GGUF, conditional LoRAs) can still
lazy-download. Failure to chmod is non-fatal.

app.py

@@ -95,6 +95,25 @@ def _bootstrap() -> None:
         sys.path.insert(0, str(comfy_dir))
     os.environ.setdefault("COMFY_MODELS_DIR", str(comfy_dir / "models"))
 
+    # Make the HF cache writable: preload_from_hub populates ~/.cache/huggingface
+    # during build, which can leave it in a state that blocks runtime
+    # hf_hub_download writes (e.g., xet's lockdir, blob targets). chmod -R u+rwX
+    # so any model NOT covered by preload (camera LoRAs, conditional GGUF, etc.)
+    # can still lazy-download. Failures here are non-fatal.
+    if on_spaces:
+        import subprocess
+
+        hf_cache = pathlib.Path.home() / ".cache" / "huggingface"
+        if hf_cache.exists():
+            try:
+                subprocess.run(
+                    ["chmod", "-R", "u+rwX", str(hf_cache)],
+                    check=False,
+                    timeout=30,
+                )
+            except Exception as exc:
+                print(f"[bootstrap] hf cache chmod skipped: {exc}", flush=True)
+
     # Stage placeholder input files so the workflow's hard-referenced loaders
     # (LoadImage/VHS_Load*) don't error at runtime even when the active mode
     # doesn't actually use the file. Real user uploads are placed alongside via
@@ -595,7 +614,13 @@ def _get_backend() -> backend_module.ComfyUILibraryBackend:
     return _BACKEND
 
 
-_COMFY_INPUT_DIR = pathlib.Path(__file__).parent / "comfyui" / "input"
+# Must match the comfy_dir used in _bootstrap() — on Spaces this is
+# ~/comfyui (mirroring backend.py's _comfy_dir), otherwise repo-local.
+_COMFY_INPUT_DIR = (
+    (pathlib.Path.home() / "comfyui" / "input")
+    if _on_spaces()
+    else pathlib.Path(__file__).parent / "comfyui" / "input"
+)
 
 
 def _stage_to_comfy_input(file_path) -> str | None:

models.py

@@ -177,11 +177,17 @@ def _walk_for_filenames(value, into: set[str]) -> None:
     Power Lora Loader stores its rows nested as `inputs.lora_1 = {on, lora,
     strength}` and similar — a flat values() loop misses these. Recurse
     through dicts and lists/tuples so nested filenames are caught.
+
+    Skips Power Lora Loader rows with `on: false` — those LoRAs aren't
+    actually loaded at runtime so there's no point downloading them.
     """
     if isinstance(value, str):
         if value.endswith(_MODEL_EXTS) or value == "tokenizer.model":
             into.add(value)
     elif isinstance(value, dict):
+        # Power Lora Loader row: {"on": bool, "lora": "...", "strength": ...}
+        if "on" in value and "lora" in value and not value.get("on"):
+            return
         for v in value.values():
             _walk_for_filenames(v, into)
     elif isinstance(value, (list, tuple)):