feat: 默认省略代码节点显式 main 调用

- 新节点仅生成 main 与 return 并同步输入形参

- Python 运行时按配置顺序传入独立参数值

- 保留历史显式调用和单对象参数写法

easyflow-modules/easyflow-module-ai/src/test/java/tech/easyflow/ai/easyagentsflow/code/PythonRuntimeEngineTest.java

@@ -2,12 +2,14 @@ package tech.easyflow.ai.easyagentsflow.code;
 
 import com.easyagents.flow.core.chain.Chain;
 import com.easyagents.flow.core.chain.ChainDefinition;
+import com.easyagents.flow.core.chain.Parameter;
 import com.easyagents.flow.core.chain.repository.InMemoryChainStateRepository;
 import com.easyagents.flow.core.node.CodeNode;
 import org.junit.Assert;
 import org.junit.Assume;
 import org.junit.Test;
 
+import java.util.Arrays;
 import java.util.Map;
 import java.util.UUID;
 
@@ -64,6 +66,38 @@ public class PythonRuntimeEngineTest {
         Assert.assertEquals(Boolean.FALSE, result.get("has_ambient"));
     }
 
+    /**
+     * 验证新节点按配置顺序把输入值传给 main 的独立形参。
+     */
+    @Test
+    public void testExecuteMainWithNamedArguments() {
+        Assume.assumeTrue(PythonRuntimeEngine.probe(PYTHON_COMMAND, 1500L).isAvailable());
+
+        Chain chain = createChain();
+        CodeNode node = (CodeNode) chain.getDefinition().getNodeById("code-test");
+        node.setParameters(Arrays.asList(
+                new Parameter("data"),
+                new Parameter("suffix")));
+        node.setMainArgsMode(CodeNode.MAIN_ARGS_MODE_NAMED);
+        PythonRuntimeEngine engine = new PythonRuntimeEngine(
+                PYTHON_COMMAND,
+                3000L,
+                65536,
+                System.getProperty("java.io.tmpdir"));
+
+        Map<String, Object> result = engine.execute(
+                String.join("\n",
+                        "def main(data, suffix):",
+                        "    return {'answer': data + suffix}"),
+                node,
+                chain,
+                Map.of(
+                        "suffix", "111",
+                        "data", "hello"));
+
+        Assert.assertEquals("hello111", result.get("answer"));
+    }
+
     @Test
     public void testLegacyResultTakesPrecedenceOverMain() {
         Assume.assumeTrue(PythonRuntimeEngine.probe(PYTHON_COMMAND, 1500L).isAvailable());
@@ -88,6 +122,35 @@ public class PythonRuntimeEngineTest {
         Assert.assertEquals("legacy", result.get("source"));
     }
 
+    /**
+     * 验证显式调用返回空字典时不会再次自动调用 main。
+     */
+    @Test
+    public void testEmptyExplicitResultDoesNotInvokeMainAgain() {
+        Assume.assumeTrue(PythonRuntimeEngine.probe(PYTHON_COMMAND, 1500L).isAvailable());
+
+        Chain chain = createChain();
+        CodeNode node = (CodeNode) chain.getDefinition().getNodeById("code-test");
+        PythonRuntimeEngine engine = new PythonRuntimeEngine(
+                PYTHON_COMMAND,
+                3000L,
+                65536,
+                System.getProperty("java.io.tmpdir"));
+
+        Map<String, Object> result = engine.execute(
+                String.join("\n",
+                        "def main(data):",
+                        "    if not isinstance(data, str):",
+                        "        raise RuntimeError('main invoked twice')",
+                        "    return {}",
+                        "_result = main(data)"),
+                node,
+                chain,
+                Map.of("data", "hello"));
+
+        Assert.assertTrue(result.isEmpty());
+    }
+
     @Test
     public void testMainMustReturnDict() {
         Assume.assumeTrue(PythonRuntimeEngine.probe(PYTHON_COMMAND, 1500L).isAvailable());