feat(app): 服务端历史行首缩略图 + 上传中心空态引导至服务端历史

- UploadSessionPhoto 解析可选 preview；历史行首有 thumb 渲染 PhotoThumbnail
 （SizedBox 定寸——Row 内裸 AspectRatio 无界约束），缺省回退中性占位
- 上传中心整体空态加「仅本机存储」说明 + 「查看服务端历史」tonal 按钮
 （与右上 History 同路由）；「需关注」空态保持专属文案不加引导
- l10n 增 queueEmptyDeviceHint / queueViewServerHistory

Co-Authored-By: Claude Code <noreply@anthropic.com>

apps/mobile/lib/l10n/app_en.arb

@@ -230,6 +230,8 @@
   "queueTimeLast7Days": "Last 7 days",
   "queueTimeLast30Days": "Last 30 days",
   "queueEmpty": "No upload tasks",
+  "queueEmptyDeviceHint": "Upload records live on this device only and are cleared on reinstall",
+  "queueViewServerHistory": "View server history",
   "queueRetryAllFailed": "Retry all failed",
   "queueAttemptCount": "{count} attempt(s)",
   "@queueAttemptCount": {