add data source

backend/app/core/files.py

@@ -0,0 +1,18 @@
+import os
+from pathlib import Path
+from typing import Optional
+
+def resolve_upload_file_path(file_url: Optional[str]) -> Path:
+    if not file_url:
+        raise ValueError("File URL is empty")
+        
+    if file_url.startswith("local://"):
+        raw_name = file_url.replace("local://", "", 1)
+        safe_name = os.path.basename(raw_name)
+        # Assuming we are in backend/app/core, go up to backend/data/uploads
+        upload_dir = Path(__file__).resolve().parents[2] / "data" / "uploads"
+        file_path = upload_dir / safe_name
+        return file_path
+    
+    # If it's already an absolute path (or relative path not starting with local://)
+    return Path(file_url)