Lazy load SSTGNN optional dependencies

modules/m3_sstgnn.py

@@ -2,10 +2,6 @@ from __future__ import annotations
 
 import torch
 from huggingface_hub import hf_hub_download
-from torch_geometric.data import Batch
-
-from modules.sstgnn_model import SSTGNN
-from utils.graph import video_to_graph
 
 
 class SSTGNNModule:
@@ -19,6 +15,8 @@ class SSTGNNModule:
                 filename="sstgnn_best.pt",
                 cache_dir=cache_dir,
             )
+            from modules.sstgnn_model import SSTGNN
+
             self.model = SSTGNN(patch_feat_dim=8, hidden_dim=128, num_frames=32)
             self.model.load_state_dict(torch.load(ckpt_path, map_location="cpu"))
             self.model.eval()
@@ -45,6 +43,10 @@ class SSTGNNModule:
         if not self.available:
             return {"s3": 0.5, "vram_mb": 0, "note": f"module_unavailable: {self.load_error}"}
 
+        from torch_geometric.data import Batch
+
+        from utils.graph import video_to_graph
+
         graph = video_to_graph(video_path, patch_size=16, max_frames=32)
         batch = Batch.from_data_list([graph.to(self.device)])
         logits = self.model(batch)