fix: use huggingface_hub to resolve LFS pointers at runtime

urllib can't follow HF's Xet CDN redirects for LFS files.
Switched to hf_hub_download which handles auth and storage
backends properly.

requirements.txt

@@ -22,3 +22,4 @@ pytest>=9.0.0
 pytest-cov>=5.0.0
 face_detection @ git+https://github.com/elliottzheng/face-detection
 gdown>=5.0.0
+huggingface_hub

resolve_lfs.py

@@ -1,11 +1,12 @@
 """Resolve Git LFS pointers left by HF Docker builds."""
 import os
-import urllib.request
+import subprocess
+import sys
 
-SPACE = os.environ.get("SPACE_ID", "FocusGuard/final")
-BASE = f"https://huggingface.co/spaces/{SPACE}/resolve/main"
 
-FILES = [
+SPACE_ID = os.environ.get("SPACE_ID", "FocusGuard/final")
+
+LFS_FILES = [
     "checkpoints/scaler_mlp.joblib",
     "checkpoints/hybrid_combiner.joblib",
     "checkpoints/meta_best.npz",
@@ -21,16 +22,25 @@ def _is_lfs_pointer(path):
 
 
 def resolve():
-    for rel in FILES:
+    try:
+        from huggingface_hub import hf_hub_download
+    except ImportError:
+        subprocess.check_call([sys.executable, "-m", "pip", "install", "-q", "huggingface_hub"])
+        from huggingface_hub import hf_hub_download
+
+    for rel in LFS_FILES:
         if not _is_lfs_pointer(rel):
-            sz = os.path.getsize(rel)
-            print(f"[OK] {rel} ({sz} bytes)")
+            print(f"[OK] {rel} ({os.path.getsize(rel)} bytes)")
             continue
-        url = f"{BASE}/{rel}"
         print(f"[LFS] Downloading {rel} ...")
         try:
-            os.makedirs(os.path.dirname(rel), exist_ok=True)
-            urllib.request.urlretrieve(url, rel)
+            local = hf_hub_download(
+                repo_id=SPACE_ID,
+                filename=rel,
+                repo_type="space",
+                local_dir=".",
+                local_dir_use_symlinks=False,
+            )
             print(f"  -> {os.path.getsize(rel)} bytes")
         except Exception as e:
             print(f"  WARN: {e}")