N-th fix od model DL

packages/node/meshnet_node/startup.py

@@ -43,7 +43,9 @@ def _full_model_sources(model_sources: list[dict]) -> list[dict]:
             full_sources.append({
                 **source,
                 "url": full_url,
-                "files": [],
+                # full_files (when advertised) enables robust per-file download
+                # of the whole snapshot; empty list falls back to the tar stream.
+                "files": source.get("full_files") or [],
                 "type": f"{source.get('type') or 'model-source'}-full",
             })
     return full_sources