fix: 避免空引用集合触发无效查询

- Agent 与 Skill 引用查询在空 ID 集合时直接返回

- 补充不调用 listByIds 的回归测试

easyflow-modules/easyflow-module-agent/src/main/java/tech/easyflow/agent/service/impl/AgentSkillReferenceProvider.java

@@ -51,6 +51,9 @@ public class AgentSkillReferenceProvider implements SkillReferenceProvider {
                 ids.add(agent.getId());
             }
         }
+        if (ids.isEmpty()) {
+            return List.of();
+        }
         List<String> result = new ArrayList<>();
         for (Agent agent : agentService.listByIds(ids)) {
             result.add("智能体“" + (agent.getName() == null ? "未命名智能体" : agent.getName()) + "”");

easyflow-modules/easyflow-module-agent/src/test/java/tech/easyflow/agent/service/impl/AgentSkillReferenceProviderTest.java

@@ -50,6 +50,22 @@ public class AgentSkillReferenceProviderTest {
                 "智能体“线上引用智能体”"), references);
     }
 
+    /**
+     * 没有 Agent 引用 Skill 时不应执行空主键集合查询。
+     */
+    @Test
+    public void shouldSkipEntityQueryWhenSkillHasNoReferences() {
+        AgentService agentService = Mockito.mock(AgentService.class);
+        AgentSkillBindingService bindingService = Mockito.mock(AgentSkillBindingService.class);
+        Mockito.when(bindingService.list(Mockito.any(QueryWrapper.class))).thenReturn(List.of());
+        Mockito.when(agentService.list(Mockito.any(QueryWrapper.class))).thenReturn(List.of());
+        AgentSkillReferenceProvider provider = new AgentSkillReferenceProvider(
+                agentService, bindingService);
+
+        Assert.assertTrue(provider.listReferences(BigInteger.TEN).isEmpty());
+        Mockito.verify(agentService, Mockito.never()).listByIds(Mockito.anyCollection());
+    }
+
     /**
      * 创建 Agent 摘要。
      *