fix(usage): 修复含失败信号的 pending 请求被误判为活跃的问题

- pending/streaming 状态含 status_code >= 400 或 error_message 时视为 failed
- 候选状态派生改为 failed 优先于 stale pending/streaming
- 活跃请求轮询时保留失败信号字段的更新
- 图片流支持 partial_image 事件转发及从 response.completed 读取最终图片

frontend/src/features/usage/composables/useUsageFilters.ts

@@ -1,6 +1,11 @@
 import { ref, computed, type Ref } from 'vue'
 import type { UsageRecord, FilterStatusValue } from '../types'
-import { hasUsageFallback, isUsageRecordFailed, isUsageUpstreamStream } from '../utils/status'
+import {
+  hasUsageFallback,
+  isUsageRecordFailed,
+  isUsageUpstreamStream,
+  resolveDisplayRequestStatus,
+} from '../utils/status'
 
 export interface UseUsageFiltersOptions {
   /** 所有记录的响应式引用 */
@@ -73,7 +78,8 @@ export function useUsageFilters(options: UseUsageFiltersOptions) {
         )
       } else if (filterStatus.value === 'active') {
         records = records.filter(record =>
-          record.status === 'pending' || record.status === 'streaming'
+          resolveDisplayRequestStatus(record) === 'pending' ||
+          resolveDisplayRequestStatus(record) === 'streaming'
         )
       } else if (filterStatus.value === 'failed') {
         records = records.filter(record => isUsageRecordFailed(record))