feat: 完成 echo 示例节点

wov_node_echo/__init__.py

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+"""WOV example echo node."""

wov_node_echo/__main__.py

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+from __future__ import annotations
+
+import json
+from pathlib import Path
+
+from wov_sdk.models import InvokeRequest, InvokeResponse, NodeManifest
+from wov_sdk.server import run_node
+
+
+def _resolve_input_text(request: InvokeRequest, node_root: Path) -> str:
+    text = request.inputs.get("text")
+    if text is not None:
+        return str(text)
+
+    file_uri = request.inputs.get("file_uri")
+    if file_uri:
+        path = Path(file_uri)
+        if not path.is_absolute():
+            path = node_root / path
+        return path.read_text(encoding="utf-8")
+
+    return "echo"
+
+
+def invoke(request: InvokeRequest) -> InvokeResponse:
+    node_root = Path(__file__).resolve().parent.parent
+    output_dir = Path(request.output_dir)
+    output_dir.mkdir(parents=True, exist_ok=True)
+
+    text = _resolve_input_text(request, node_root)
+    output_path = output_dir / "echo.txt"
+    output_path.write_text(text, encoding="utf-8")
+
+    return InvokeResponse(
+        status="completed",
+        outputs={
+            "text": text,
+            "file_uri": str(output_path),
+        },
+    )
+
+
+def main() -> None:
+    manifest_path = Path(__file__).resolve().parent.parent / "node.manifest.json"
+    with open(manifest_path, "r", encoding="utf-8") as f:
+        manifest = NodeManifest.from_dict(json.load(f))
+    run_node(manifest, invoke)
+
+
+if __name__ == "__main__":
+    main()