Add loguru/tqdm/torchdiffeq; make wandb optional

cell_fm/logging/loggers.py

@@ -9,7 +9,12 @@ from loguru import logger
 from cell_fm.utils.dist_utils import is_master_node
 from transformers import TrainerCallback
 
-import wandb  # isort:skip
+# wandb is only used by the training callback below. The demo Space never trains,
+# so it is optional here rather than a required install.
+try:
+    import wandb  # isort:skip
+except ImportError:  # pragma: no cover
+    wandb = None
 
 handlers = {}
 
@@ -65,7 +70,7 @@ class MetricLogger(object):
                 log_data[k] = log_data[k].detach().item()
 
         logger.info(" | ".join([f"{k}={v:.4g}" for k, v in log_data.items()]))
-        if wandb.run is not None:
+        if wandb is not None and wandb.run is not None:
             # Add prefix
             if prefix:
                 log_data = {f"{prefix}/{k}": v for k, v in log_data.items()}

requirements.txt

@@ -16,6 +16,11 @@ einops==0.8.0
 huggingface_hub>=0.24.6
 gradio>=4.44.0
 
+# pulled in by the vendored cell_fm modules
+loguru
+tqdm
+torchdiffeq        # ODE solver behind the flow-matching sampler
+
 # flash-attn is deliberately NOT installed. ESM-C falls back to its pure-torch
 # rotary when the package is absent (esm/models/esmc.py: is_flash_attn_available),
 # and the two paths were verified bit-identical -- same AUC, same AAC, same 256/256