feat: add clear failed task action / 添加清理失败记录入口

[Chenzr888]

摘要 / Summary

• 在画廊状态筛选旁新增紧凑垃圾桶按钮 / Add a compact trash action next to the gallery status filter
• 清理所有失败生成记录前弹出确认框 / Confirm before clearing all failed generation records
• 通过 clearFailedTasks() 复用现有批量删除流程 / Reuse the existing multi-task deletion flow via clearFailedTasks()
• 增加 store 测试，验证完成任务和运行任务会被保留 / Cover the action with a store test that preserves done and running tasks

Closes #94

验证 / Verification

• npm test
• npm run build