feat(mobile): upload queue ui and continuous capture page

Task 9 (P3 plan): queue tab replaces the stub, continuous capture page
enqueues per shot, album detail gains an upload FAB, and the upload
engine lifecycle is now bound to the login session.

- Engine scope: session account drives UploadEngine start/stop; wired
  from app boot, login success, logout, and 401 eviction. Tasks stay in
  the store across logout (accountId hard isolation).
- Queue tab: album x state x time filter bar, task rows with thumbnail,
  state chip, localized error copy, attempt count, per-row progress via
  a broadcast progress hub, state-dependent actions (re-pick retry,
  retryNow, cancel, delete), batch retry bar, 200ms-debounced live
  refresh from drift table updates.
- Capture page: camera preview via injected CaptureSource, one enqueue
  per shutter press, persistent album/category/badges overlay with a
  switch-only-affects-new-shots hint, gallery multi-pick, exit confirm
  while uploads are pending, permission-denied and init-failure views.
- POST_NOTIFICATIONS runtime permission via a small MethodChannel
  (photolive/permissions) + PermissionPlugin.kt: single runtime
  permission need, avoids permission_handler dependency; requested once
  on first enqueue, silent degradation when denied or unavailable.
- Album detail FAB: capture-and-upload / pick-from-gallery sheet.
- l10n: ~50 new keys in zh/en arbs; tests: +45 (filter matrix, engine
  scope lifecycle, permission gate, queue tab, capture page, FAB entry);
  existing page tests updated to inject session/task-store fakes.

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

apps/mobile/lib/core/notification_permission.dart

@@ -0,0 +1,57 @@
+/// POST_NOTIFICATIONS 运行时权限门（P3 计划 Task 9）。
+///
+/// Android 13+（API 33）起，上传前台服务通知需运行时授权；未授权时
+/// 传输继续、仅通知不显示——**静默降级，永不阻断入队**（技术方案 §6.3）。
+///
+/// 实现取舍（有意不引入 permission_handler）：本 App 全部运行时权限需求
+/// 仅此一项（camera/image_picker 插件自管权限），为单个权限引入
+/// permission_handler 全家桶（AndroidX 传递依赖 + iOS Podfile 宏配置）
+/// 不成比例——复用既有原生桥接模式（Task 7 UploadPlugin 同款），自建
+/// MethodChannel `photolive/permissions`（MainActivity 内 PermissionPlugin
+/// 约 60 行 Kotlin，SDK<33 直接返回 granted）。后续再增权限需求时评估
+/// 插件化。
+///
+/// 进程内单次语义：首次入队动作（连拍/相册选择）时请求一次，之后不再
+/// 打扰；拒绝或通道失败（iOS/桌面无此通道）一律静默。
+library;
+
+import 'dart:io';
+
+import 'package:flutter/foundation.dart' show kIsWeb;
+import 'package:flutter/services.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+/// 通知权限门（注入 [channel]/[isAndroid] 供测试）。
+class NotificationPermission {
+  NotificationPermission({
+    MethodChannel? channel,
+    bool? isAndroid,
+  })  : _channel = channel ?? const MethodChannel(kChannelName),
+        _isAndroid = isAndroid ?? (!kIsWeb && Platform.isAndroid);
+
+  /// 平台通道名（与 Kotlin `PermissionPlugin.CHANNEL` 一致）。
+  static const String kChannelName = 'photolive/permissions';
+
+  final MethodChannel _channel;
+  final bool _isAndroid;
+  bool _requested = false;
+
+  /// 确保已请求一次（首次入队动作调用；幂等）。
+  ///
+  /// 非 Android 平台直接跳过（iOS 后台传输不依赖通知权限）；通道调用
+  /// 失败/拒绝静默吞掉——上传链路不因通知权限降级而中断。
+  Future<void> ensureRequested() async {
+    if (_requested) return;
+    _requested = true;
+    if (!_isAndroid) return;
+    try {
+      await _channel.invokeMethod<String>('requestPostNotifications');
+    } on Object {
+      // 通道缺失（iOS/桌面）或请求异常：静默降级。
+    }
+  }
+}
+
+/// 生产 Provider（队列/连拍页经 ref.read 一次性调用）。
+final notificationPermissionProvider =
+    Provider<NotificationPermission>((ref) => NotificationPermission());