feat: add unified asset retry endpoint

frontend/src/views/StoryDetail.vue

@@ -34,14 +34,6 @@ interface Story {
   }> | null
 }
 
-interface ImageGenerationResponse {
-  image_url: string | null
-  generation_status: string
-  image_status: string
-  audio_status: string
-  last_error: string | null
-}
-
 const route = useRoute()
 const router = useRouter()
 
@@ -93,12 +85,9 @@ async function generateImage() {
   error.value = ''
 
   try {
-    const result = await api.post<ImageGenerationResponse>(`/api/image/generate/${story.value.id}`)
-    story.value.image_url = result.image_url
-    story.value.generation_status = result.generation_status
-    story.value.image_status = result.image_status
-    story.value.audio_status = result.audio_status
-    story.value.last_error = result.last_error
+    story.value = await api.post<Story>(`/api/stories/${story.value.id}/assets/retry`, {
+      assets: ['image'],
+    })
   } catch (e) {
     error.value = e instanceof Error ? e.message : '图片生成失败'
     await refreshStorySnapshot().catch(() => undefined)