main: 增强工具调用与消息流程

- 支持 tool.call 和 tool.result 消息类型处理
- 引入 Tool 调度与执行逻辑，支持超时与结果截断
- 增加 ToolRegistry 和 ToolExecutor 管理工具定义与执行
- 更新上下文构建与消息映射逻辑，适配工具闭环处理
- 扩展配置与环境变量，支持 Tool 调用相关选项
- 增强单元测试覆盖工具调用与执行情景
- 更新文档和 OpenAPI，新增工具相关说明与模型定义

tests/Feature/AgentRunTest.php

@@ -257,4 +257,65 @@ class AgentRunTest extends TestCase
                 && ($m->payload['http_status'] ?? null) === 500;
         }));
     }
+
+    public function test_tool_call_triggers_child_run_and_continues_to_final_message(): void
+    {
+        $this->app->bind(AgentProviderInterface::class, function () {
+            return new class implements AgentProviderInterface {
+                public int $calls = 0;
+
+                public function stream(AgentContext $context, array $options = []): \Generator
+                {
+                    if ($this->calls === 0) {
+                        $this->calls++;
+                        yield ProviderEvent::toolDelta([
+                            'tool_calls' => [
+                                [
+                                    'id' => 'call_1',
+                                    'name' => 'get_time',
+                                    'arguments' => '{"format":"c"}',
+                                    'index' => 0,
+                                ],
+                            ],
+                        ]);
+                        yield ProviderEvent::done('tool_calls');
+
+                        return;
+                    }
+
+                    yield ProviderEvent::messageDelta('tool done');
+                    yield ProviderEvent::done('stop');
+                }
+            };
+        });
+
+        $service = app(ChatService::class);
+        $dispatcher = app(RunDispatcher::class);
+
+        $session = $service->createSession('Tool Run');
+        $prompt = $service->appendMessage([
+            'session_id' => $session->session_id,
+            'role' => Message::ROLE_USER,
+            'type' => 'user.prompt',
+            'content' => 'use tool',
+        ]);
+
+        $runId = $dispatcher->dispatchForPrompt($session->session_id, $prompt->message_id);
+
+        (new AgentRunJob($session->session_id, $runId))->handle(
+            app(RunLoop::class),
+            app(OutputSink::class),
+            app(CancelChecker::class)
+        );
+
+        $messages = Message::query()
+            ->where('session_id', $session->session_id)
+            ->orderBy('seq')
+            ->get();
+
+        $this->assertTrue($messages->contains(fn ($m) => $m->type === 'tool.call' && ($m->payload['tool_call_id'] ?? null) === 'call_1'));
+        $this->assertTrue($messages->contains(fn ($m) => $m->type === 'tool.result' && ($m->payload['tool_call_id'] ?? null) === 'call_1'));
+        $this->assertTrue($messages->contains(fn ($m) => $m->type === 'agent.message' && ($m->payload['run_id'] ?? null) === $runId));
+        $this->assertTrue($messages->contains(fn ($m) => $m->type === 'run.status' && ($m->payload['status'] ?? null) === 'DONE'));
+    }
 }