chore: import upstream snapshot with attribution

entity/configs/node/passthrough.py

@@ -0,0 +1,32 @@
+"""Configuration for passthrough nodes."""
+
+from dataclasses import dataclass
+from typing import Mapping, Any
+
+from entity.configs.base import BaseConfig, ConfigFieldSpec, optional_bool, require_mapping
+
+
+@dataclass
+class PassthroughConfig(BaseConfig):
+    """Configuration for passthrough nodes."""
+
+    only_last_message: bool = True
+
+    @classmethod
+    def from_dict(cls, data: Mapping[str, Any] | None, *, path: str) -> "PassthroughConfig":
+        if data is None:
+            return cls(only_last_message=True, path=path)
+        mapping = require_mapping(data, path)
+        only_last_message = optional_bool(mapping, "only_last_message", path, default=True)
+        return cls(only_last_message=only_last_message, path=path)
+
+    FIELD_SPECS = {
+        "only_last_message": ConfigFieldSpec(
+            name="only_last_message",
+            display_name="Only Last Message",
+            type_hint="bool",
+            required=False,
+            default=True,
+            description="If True, only pass the last received message. If False, pass all messages.",
+        ),
+    }