Add verified graph dataloader example

loaders/gwam_graph_dataloader.py

@@ -6,8 +6,8 @@ view_evidence, visual features, and edge records can all share the same storage
 slot id. That 256-slot axis is only a storage/alignment convention. This loader
 drops inactive padded slots and returns a ragged graph with N_real active nodes.
 
-The raw node_state channel 1 (`family_idx`) is categorical. The loader never
-feeds it as a continuous scalar feature. Use `family_encoding="onehot"` for a
+The raw node_state channel 1 (`family_idx`) is categorical. Never feed raw
+family_idx as a continuous scalar feature. Use `family_encoding="onehot"` for a
 fixed 10-D one-hot block, or `family_encoding="embedding_placeholder"` to return
 integer family ids separately for a model-side nn.Embedding.
 """