main: 引入 AgentProvider 流式事件与 OpenAI 兼容适配

- 增加流式事件流支持，Provider 输出 `message.delta` 等事件
- 实现 OpenAI 兼容适配器，包括 RequestBuilder、ApiClient 等模块
- 更新 Agent Run 逻辑，支持流式增量写入与模型完成状态管理
- 扩展配置项 `agent.openai.*`，支持模型、密钥等配置
- 优化文档，完善流式事件与消息类型说明
- 增加单元测试，覆盖 Provider 和 OpenAI 适配相关逻辑
- 更新环境变量与配置示例，支持新功能

app/Services/Agent/HttpAgentProvider.php

@@ -2,105 +2,28 @@
 
 namespace App\Services\Agent;
 
-use Illuminate\Http\Client\ConnectionException;
-use Illuminate\Support\Facades\Http;
+use App\Services\Agent\OpenAi\OpenAiChatCompletionsAdapter;
 
 class HttpAgentProvider implements AgentProviderInterface
 {
-    protected string $endpoint;
-    protected int $timeoutSeconds;
-    protected int $connectTimeoutSeconds;
-    protected int $retryTimes;
-    protected int $retryBackoffMs;
+    private readonly bool $enabled;
 
-    public function __construct(?string $endpoint = null)
+    public function __construct(private readonly OpenAiChatCompletionsAdapter $adapter)
     {
-        $this->endpoint = $endpoint ?? config('agent.provider.endpoint', '');
-        $this->timeoutSeconds = (int) config('agent.provider.timeout_seconds', 30);
-        $this->connectTimeoutSeconds = (int) config('agent.provider.connect_timeout_seconds', 5);
-        $this->retryTimes = (int) config('agent.provider.retry_times', 1);
-        $this->retryBackoffMs = (int) config('agent.provider.retry_backoff_ms', 500);
+        $baseUrl = (string) config('agent.openai.base_url', '');
+        $apiKey = (string) config('agent.openai.api_key', '');
+        $this->enabled = trim($baseUrl) !== '' && trim($apiKey) !== '';
     }
 
     /**
-     * @param array<string, mixed> $context
      * @param array<string, mixed> $options
      */
-    public function generate(array $context, array $options = []): string
+    public function stream(AgentContext $context, array $options = []): \Generator
     {
-        if (empty($this->endpoint)) {
-            // placeholder to avoid accidental outbound calls when未配置
-            return (new DummyAgentProvider())->generate($context, $options);
+        if (! $this->enabled) {
+            return (new DummyAgentProvider())->stream($context, $options);
         }
 
-        $payload = [
-            'context' => $context,
-            'options' => $options,
-        ];
-
-        $attempts = $this->retryTimes + 1;
-        $lastException = null;
-        $lastResponseBody = null;
-        $lastStatus = null;
-
-        for ($attempt = 1; $attempt <= $attempts; $attempt++) {
-            try {
-                $response = Http::connectTimeout($this->connectTimeoutSeconds)
-                    ->timeout($this->timeoutSeconds)
-                    ->post($this->endpoint, $payload);
-
-                $lastStatus = $response->status();
-                $lastResponseBody = $response->body();
-
-                if ($response->successful()) {
-                    $data = $response->json();
-
-                    return is_string($data) ? $data : ($data['content'] ?? '');
-                }
-
-                $retryable = $lastStatus === 429 || $lastStatus >= 500;
-                if ($retryable && $attempt < $attempts) {
-                    usleep($this->retryBackoffMs * 1000);
-                    continue;
-                }
-
-                throw new ProviderException(
-                    'HTTP_ERROR',
-                    'Agent provider failed',
-                    $retryable,
-                    $lastStatus,
-                    $lastResponseBody
-                );
-            } catch (ConnectionException $exception) {
-                $lastException = $exception;
-                if ($attempt < $attempts) {
-                    usleep($this->retryBackoffMs * 1000);
-                    continue;
-                }
-            } catch (\Throwable $exception) {
-                $lastException = $exception;
-                break;
-            }
-        }
-
-        $rawMessage = $lastException ? $lastException->getMessage() : $lastResponseBody;
-
-        if ($lastException instanceof ConnectionException) {
-            throw new ProviderException(
-                'CONNECTION_FAILED',
-                'Agent provider connection failed',
-                true,
-                $lastStatus,
-                $rawMessage
-            );
-        }
-
-        throw new ProviderException(
-            'UNKNOWN_ERROR',
-            'Agent provider error',
-            false,
-            $lastStatus,
-            $rawMessage
-        );
+        return $this->adapter->stream($context, $options);
     }
 }