chore: import upstream snapshot with attribution

runtime/node/executor/literal_executor.py

@@ -0,0 +1,29 @@
+"""Literal node executor."""
+
+from typing import List
+
+from entity.configs import Node
+from entity.configs.node.literal import LiteralNodeConfig
+from entity.messages import Message
+from runtime.node.executor.base import NodeExecutor
+
+
+class LiteralNodeExecutor(NodeExecutor):
+    """Emit the configured literal message whenever triggered."""
+
+    def execute(self, node: Node, inputs: List[Message]) -> List[Message]:
+        if node.node_type != "literal":
+            raise ValueError(f"Node {node.id} is not a literal node")
+
+        config = node.as_config(LiteralNodeConfig)
+        if config is None:
+            raise ValueError(f"Node {node.id} missing literal configuration")
+
+        self._ensure_not_cancelled()
+        return [self._build_message(
+            role=config.role,
+            content=config.content,
+            source=node.id,
+            preserve_role=True,
+        )]
+