fix: 修复阿里生图模型动态占位卡片不显示问题

- 在 chat.tsx 中添加 alibaba-image 类型到 startGeneration
- 确保 pendingGeneration 记录正确的 modelType

components/chat.tsx

@@ -356,6 +356,7 @@ export function Chat({
       else if (model?.providerType === "volcano-vision") modelType = "volcano-vision";
       else if (model?.providerType === "volcano-video") modelType = "volcano-video";
       else if (model?.providerType === "qianwen-video") modelType = "qianwen-video";
+      else if (model?.providerType === "alibaba-image") modelType = "alibaba-image";
       
       console.log(`[Chat] 🚀 记录生成任务: modelType=${modelType}, modelId=${currentModelId}`);
       startGeneration(currentModelId, modelType);