Create model_loader.py

backend/model_loader.py

@@ -0,0 +1,19 @@
+import os
+import shutil
+from huggingface_hub import snapshot_download, HfApi
+from .civitai import download_civitai_model
+
+def prepare_model(source: str, model_id: str, civitai_key: str = None) -> str:
+    if source == "hf":
+        # Use cache, but ensure safetensors available
+        try:
+            path = snapshot_download(model_id, cache_dir="/data/hf_cache")
+            return path
+        except Exception as e:
+            raise RuntimeError(f"Failed to download HF model {model_id}: {e}")
+    elif source == "civitai":
+        if not civitai_key:
+            raise ValueError("Civitai API key required")
+        return download_civitai_model(model_id, civitai_key)
+    else:
+        raise ValueError(f"Unknown source: {source}")