main: 扩展 Agent Run 调度与队列功能

- 增加 Agent Run MVP-0，包括 RunDispatcher 和 AgentRunJob
- 优化队列配置，支持 Redis 队列驱动，添加 Horizon 容器
- 更新 Docker 配置，细化角色分工，新增 Horizon 配置
- 增加测试任务 `TestJob`，扩展队列使用示例
- 更新 OpenAPI 规范，添加 Agent Run 相关接口及示例
- 编写文档，详细描述 Agent Run 流程与 MVP-0 功能
- 优化相关服务与文档，支持队列与异步运行

app/Services/ContextBuilder.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace App\Services;
+
+use App\Models\Message;
+use Illuminate\Support\Collection;
+
+class ContextBuilder
+{
+    public function __construct(private readonly int $limit = 20)
+    {
+    }
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function build(string $sessionId, string $runId): array
+    {
+        $messages = $this->loadRecentMessages($sessionId);
+
+        return [
+            'run_id' => $runId,
+            'session_id' => $sessionId,
+            'system_prompt' => 'You are an agent inside ARS. Respond concisely in plain text.',
+            'messages' => $messages->map(function (Message $message) {
+                return [
+                    'message_id' => $message->message_id,
+                    'role' => $message->role,
+                    'type' => $message->type,
+                    'content' => $message->content,
+                    'seq' => $message->seq,
+                ];
+            })->values()->all(),
+        ];
+    }
+
+    private function loadRecentMessages(string $sessionId): Collection
+    {
+        return Message::query()
+            ->where('session_id', $sessionId)
+            ->whereIn('role', [Message::ROLE_USER, Message::ROLE_AGENT])
+            ->whereIn('type', ['user.prompt', 'agent.message'])
+            ->orderByDesc('seq')
+            ->limit($this->limit)
+            ->get()
+            ->sortBy('seq')
+            ->values();
+    }
+}