fix: 修复工作流入口标题与提示词校验

- 支持系统入口标题清空占位与下游引用展示同步

- 降低字段编辑触发的节点图重算和无效渲染

- 在保存及执行前拦截空白的大模型用户提示词

easyflow-modules/easyflow-module-ai/src/test/java/tech/easyflow/ai/easyagentsflow/service/WorkflowCheckServiceTest.java

@@ -436,6 +436,41 @@ public class WorkflowCheckServiceTest {
         assertHasCode(result, "SEARCH_DATASET_INVALID");
     }
 
+    /**
+     * 验证保存阶段拒绝空白的大模型用户提示词。
+     */
+    @Test
+    public void testSaveShouldBlockBlankLlmUserPrompt() throws Exception {
+        WorkflowCheckService service = newService(new HashMap<>());
+        JSONObject llmData = data("大模型");
+        llmData.put("userPrompt", "   ");
+        String content = workflowJson(
+                array(node("llm-1", "llmNode", null, llmData)),
+                new JSONArray()
+        );
+
+        WorkflowCheckResult result = service.checkContent(content, WorkflowCheckStage.SAVE, null);
+        Assert.assertFalse(result.isPassed());
+        assertHasCode(result, "LLM_USER_PROMPT_EMPTY");
+    }
+
+    /**
+     * 验证保存阶段接受有效的大模型用户提示词。
+     */
+    @Test
+    public void testSaveShouldPassNonBlankLlmUserPrompt() throws Exception {
+        WorkflowCheckService service = newService(new HashMap<>());
+        JSONObject llmData = data("大模型");
+        llmData.put("userPrompt", "{{start-1.user_input}}");
+        String content = workflowJson(
+                array(node("llm-1", "llmNode", null, llmData)),
+                new JSONArray()
+        );
+
+        WorkflowCheckResult result = service.checkContent(content, WorkflowCheckStage.SAVE, null);
+        Assert.assertTrue(result.isPassed());
+    }
+
     @Test
     public void testPreExecuteShouldBlockMissingStartOrEnd() throws Exception {
         WorkflowCheckService service = newService(new HashMap<>());
@@ -453,6 +488,34 @@ public class WorkflowCheckServiceTest {
         assertHasCode(result, "END_NODE_MISSING");
     }
 
+    /**
+     * 验证执行前校验拒绝空的大模型用户提示词。
+     */
+    @Test
+    public void testPreExecuteShouldBlockEmptyLlmUserPrompt() throws Exception {
+        WorkflowCheckService service = newService(new HashMap<>());
+        JSONObject llmData = data("大模型");
+        llmData.put("userPrompt", "");
+        String content = workflowJson(
+                array(
+                        node("s1", "startNode", null, data("开始")),
+                        node("llm-1", "llmNode", null, llmData),
+                        node("e1", "endNode", null, data("结束"))
+                ),
+                array(
+                        edge("edge-1", "s1", "llm-1"),
+                        edge("edge-2", "llm-1", "e1")
+                )
+        );
+
+        WorkflowCheckResult result = service.checkContent(
+                content,
+                WorkflowCheckStage.PRE_EXECUTE,
+                BigInteger.ONE);
+        Assert.assertFalse(result.isPassed());
+        assertHasCode(result, "LLM_USER_PROMPT_EMPTY");
+    }
+
     @Test
     public void testPreExecuteShouldPassForSourceOnlySearchDatasetNode() throws Exception {
         WorkflowCheckService service = newService(new HashMap<>());