tracker download fix

packages/node/meshnet_node/downloader.py

@@ -213,6 +213,47 @@ def _allow_patterns_from_sources(model_sources: list[dict]) -> list[str] | None:
     return sorted(patterns) if patterns else None
 
 
+def _allow_patterns_from_remote_index(
+    hf_repo: str,
+    cache_dir: Path,
+    shard_start: int,
+    shard_end: int,
+) -> list[str] | None:
+    """Fetch just the SafeTensors index + config (a few KB) from HF and compute
+    which weight files the assigned layer range needs, so a HuggingFace fallback
+    download stays layer-scoped even when the tracker has no model_sources
+    (e.g. it has no local snapshot for this repo cached yet)."""
+    try:
+        from huggingface_hub import hf_hub_download  # type: ignore[import]
+
+        from .safetensors_selection import (
+            INDEX_FILENAME,
+            METADATA_FILENAMES,
+            layers_from_config_dict,
+            select_files_for_layers_from_index,
+        )
+
+        index_path = hf_hub_download(repo_id=hf_repo, filename=INDEX_FILENAME, cache_dir=str(cache_dir))
+        weight_map = json.loads(Path(index_path).read_text(encoding="utf-8")).get("weight_map")
+    except Exception:
+        return None
+    if not isinstance(weight_map, dict):
+        return None
+
+    total_layers: int | None = None
+    try:
+        config_path = hf_hub_download(repo_id=hf_repo, filename="config.json", cache_dir=str(cache_dir))
+        config = json.loads(Path(config_path).read_text(encoding="utf-8"))
+        total_layers = layers_from_config_dict(config)
+    except Exception:
+        pass
+
+    selected = select_files_for_layers_from_index(
+        weight_map, shard_start, shard_end, total_layers=total_layers
+    )
+    return sorted(selected | METADATA_FILENAMES)
+
+
 def download_shard(
     model: str,
     shard_start: int,
@@ -285,7 +326,14 @@ def download_shard(
         if raced is not None:
             return raced[1]
 
+    allow_patterns = _allow_patterns_from_remote_index(hf_repo, cache_dir, shard_start, shard_end)
     if progress:
-        print("  download source: HuggingFace", flush=True)
+        if allow_patterns:
+            print("  download source: HuggingFace (layer-filtered)", flush=True)
+        else:
+            print(
+                "  download source: HuggingFace (full snapshot — no SafeTensors index found)",
+                flush=True,
+            )
 
-    return _download_huggingface_subset(hf_repo, cache_dir, shard_dir, None)
+    return _download_huggingface_subset(hf_repo, cache_dir, shard_dir, allow_patterns)