fix(cp): prevent recursion error in wrapper and injection

- Add safety check in CPAttentionWrapper.__getattr__

- Add idempotency check in BaseRingModel.set_cp_adapter

Author: jaisw7

src/dnet/core/models/base.py

@@ -42,6 +42,11 @@ def set_cp_adapter(self, adapter: Any) -> None:
         layers = getattr(self, "layers", []) or []
         for i, layer in enumerate(layers):
             if hasattr(layer, "self_attn"):
+                # Avoid double-wrapping
+                if isinstance(layer.self_attn, CPAttentionWrapper):
+                    logger.debug("Layer %d already has CP adapter, skipping wrap", i)
+                    continue
+
                 # Wrap existing attention module
                 layer.self_attn = CPAttentionWrapper(layer.self_attn, adapter)
 

src/dnet/core/models/cp_layers.py

@@ -111,4 +111,9 @@ def __call__(
         return output
 
     def __getattr__(self, name: str):
+        if name == "base_attn":
+            # Prevent infinite recursion if base_attn is missing
+            raise AttributeError(
+                f"'{type(self).__name__}' object has no attribute 'base_attn'"
+            )
         return getattr(self.base_attn, name)