make downloaded weights persistent, remove erronous len for rf3d output

app.py

@@ -15,9 +15,14 @@ from rfd3.engine import RFD3InferenceConfig, RFD3InferenceEngine
 
 cmd =  "foundry install rfd3 ligandmpnn rf3"
 print("Global PATH:", os.environ.get("PATH"))
+
+os.environ["HF_HOME"] = "/data"  # HF Spaces persistent dir
+os.environ["FOUNDRY_CHECKPOINT_DIRS"] = "/data/checkpoints"
+
 result = subprocess.run(cmd, shell=True, capture_output=True, text=True)
 if result.returncode == 0:
     print("Models installed successfully.")
+    print(result.stdout)
 else:   
     print(f"Error installing models: {result.stderr}")
 
@@ -89,7 +94,7 @@ def test_rfd3_from_notebook():
         for idx, data in outputs.items():
             return_str += f"Batch {idx}: {len(data)} structure(s)\n"
             for i, struct in enumerate(data):
-                return_str += f"Structure {i+1}: {len(struct)} atoms\n"
+                return_str += f"Structure {i+1}:\n"
                 return_str += struct.atom_array
         return return_str
     except Exception as e: