feat: 增加 system 消息格式配置

- 模型管理支持选择字符串或内容块数组格式

- 验证连接携带 system 消息并复用正式运行时模型配置

- 补充配置映射与验证消息角色测试

easyflow-modules/easyflow-module-agent/src/test/java/tech/easyflow/agent/runtime/AgentRuntimeCompilerModelConfigTest.java

@@ -4,6 +4,7 @@ import com.easyagents.agent.runtime.memory.AgentMemoryPolicy;
 import com.easyagents.agent.runtime.model.AgentGenerationOptions;
 import com.easyagents.agent.runtime.model.AgentHttpVersionPolicy;
 import com.easyagents.agent.runtime.model.AgentModelSpec;
+import com.easyagents.agent.runtime.model.AgentSystemContentFormat;
 import org.junit.Assert;
 import org.junit.Test;
 import tech.easyflow.agent.entity.Agent;
@@ -66,6 +67,36 @@ public class AgentRuntimeCompilerModelConfigTest {
         Assert.assertEquals(AgentHttpVersionPolicy.AUTO, spec.getHttpVersionPolicy());
     }
 
+    /**
+     * 验证模型 options 中的 system content 格式会编译到中立模型声明。
+     *
+     * @throws Exception 反射调用失败时抛出
+     */
+    @Test
+    public void modelSystemContentFormatShouldCompileFromOptions() throws Exception {
+        Model model = model(Map.of("agentSystemContentFormat", "TEXT_PARTS"));
+        AgentRuntimeCompiler compiler = compiler(model);
+
+        AgentModelSpec spec = invokeModelSpec(compiler);
+
+        Assert.assertEquals(AgentSystemContentFormat.TEXT_PARTS, spec.getSystemContentFormat());
+    }
+
+    /**
+     * 验证未知 system content 格式安全回退到字符串。
+     *
+     * @throws Exception 反射调用失败时抛出
+     */
+    @Test
+    public void unknownSystemContentFormatShouldFallbackToString() throws Exception {
+        Model model = model(Map.of("agentSystemContentFormat", "PARTS"));
+        AgentRuntimeCompiler compiler = compiler(model);
+
+        AgentModelSpec spec = invokeModelSpec(compiler);
+
+        Assert.assertEquals(AgentSystemContentFormat.STRING, spec.getSystemContentFormat());
+    }
+
     /**
      * 验证 EasyFlow 忽略新旧消息数阈值，仅保留 Token 压缩配置。
      *

easyflow-modules/easyflow-module-agent/src/test/java/tech/easyflow/agent/runtime/AgentScopeChatModelConnectivityVerifierTest.java

@@ -7,6 +7,7 @@ import com.easyagents.agent.runtime.model.AgentModelSpec;
 import io.agentscope.core.message.Base64Source;
 import io.agentscope.core.message.ImageBlock;
 import io.agentscope.core.message.Msg;
+import io.agentscope.core.message.MsgRole;
 import io.agentscope.core.message.TextBlock;
 import io.agentscope.core.model.ChatResponse;
 import io.agentscope.core.model.GenerateOptions;
@@ -48,6 +49,7 @@ public class AgentScopeChatModelConnectivityVerifierTest {
         Assert.assertEquals("HTTP_1_1", result.getEffectiveHttpVersion());
         Assert.assertEquals(List.of(false, true), factory.getFactoryStreams());
         Assert.assertEquals(List.of(false, true), factory.getRequestStreams());
+        Assert.assertEquals(List.of(MsgRole.SYSTEM, MsgRole.USER), factory.getMessageRoles().get(0));
         Assert.assertEquals(List.of(false, false), factory.getEnableThinkingValues());
         Assert.assertEquals(List.of(false, false), factory.getChatTemplateThinkingValues());
     }
@@ -190,6 +192,8 @@ public class AgentScopeChatModelConnectivityVerifierTest {
         private final List<Boolean> requestStreams = new ArrayList<>();
         /** 模型请求收到的消息。 */
         private final List<Msg> messages = new ArrayList<>();
+        /** 各阶段请求消息的角色顺序。 */
+        private final List<List<MsgRole>> messageRoles = new ArrayList<>();
         /** OpenAI-compatible 请求中的思考开关。 */
         private final List<Object> enableThinkingValues = new ArrayList<>();
         /** GPUStack 模板参数中的思考开关。 */
@@ -241,7 +245,8 @@ public class AgentScopeChatModelConnectivityVerifierTest {
                         List<ToolSchema> tools,
                         GenerateOptions options) {
                     requestStreams.add(Boolean.TRUE.equals(options.getStream()));
-                    messages.add(inputMessages.get(0));
+                    messages.add(inputMessages.get(inputMessages.size() - 1));
+                    messageRoles.add(inputMessages.stream().map(Msg::getRole).toList());
                     return responses;
                 }
 
@@ -284,6 +289,15 @@ public class AgentScopeChatModelConnectivityVerifierTest {
             return messages;
         }
 
+        /**
+         * 获取各阶段请求消息的角色顺序。
+         *
+         * @return 消息角色顺序
+         */
+        private List<List<MsgRole>> getMessageRoles() {
+            return messageRoles;
+        }
+
         /**
          * 获取 OpenAI-compatible 请求中的思考开关。
          *