fix: handle grok2 synchronous video response, skip async polling

src/lib/model-gateway/openai-compat/video.ts

@@ -176,6 +176,15 @@ export async function generateVideoViaOpenAICompat(request: OpenAICompatVideoReq
     input_reference: inputReference,
   } as Parameters<typeof client.videos.create>[0])
 
+  // 同步完成的情况（如 grok2api）：响应里直接携带 url 和 status=completed
+  const rawResponse = response as unknown as Record<string, unknown>
+  if (rawResponse.status === 'completed' && typeof rawResponse.url === 'string' && rawResponse.url) {
+    return {
+      success: true,
+      videoUrl: rawResponse.url as string,
+    }
+  }
+
   if (!response.id || typeof response.id !== 'string') {
     throw new Error('OPENAI_COMPAT_VIDEO_CREATE_INVALID_RESPONSE: missing video id')
   }