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/pages/home_page.dart

@@ -2,8 +2,10 @@ import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 
 import '../core/api_client.dart';
+import '../features/uploads/engine_scope.dart';
 import '../l10n/app_localizations.dart';
 import 'albums_tab.dart';
+import 'queue_tab.dart';
 
 /// 主壳：底部导航（相册 / 队列 / 设置）。
 class HomePage extends StatefulWidget {
@@ -54,45 +56,6 @@ class _HomePageState extends State<HomePage> {
   }
 }
 
-/// 上传队列（桩）。Task 9：状态机展示、筛选与重试；当前仅提供
-/// 服务端上传历史入口（A19 跨设备记录）。
-class QueueTab extends StatelessWidget {
-  const QueueTab({super.key});
-
-  @override
-  Widget build(BuildContext context) {
-    final l10n = AppLocalizations.of(context);
-    final theme = Theme.of(context);
-    return Scaffold(
-      appBar: AppBar(title: Text(l10n.queue)),
-      body: Center(
-        child: Column(
-          mainAxisSize: MainAxisSize.min,
-          children: [
-            Padding(
-              padding: const EdgeInsets.symmetric(horizontal: 32),
-              child: Text(
-                l10n.queueStubHint,
-                textAlign: TextAlign.center,
-                style: theme.textTheme.bodyMedium?.copyWith(
-                  color: theme.colorScheme.onSurfaceVariant,
-                ),
-              ),
-            ),
-            const SizedBox(height: 16),
-            FilledButton.tonalIcon(
-              onPressed: () =>
-                  Navigator.of(context).pushNamed('/server-history'),
-              icon: const Icon(Icons.history_outlined),
-              label: Text(l10n.serverHistoryEntry),
-            ),
-          ],
-        ),
-      ),
-    );
-  }
-}
-
 /// 设置页（P3 Task 3：修改密码入口 + 退出登录；Task 10 补语言切换持久化）。
 class SettingsTab extends ConsumerWidget {
   const SettingsTab({super.key});
@@ -100,6 +63,8 @@ class SettingsTab extends ConsumerWidget {
   Future<void> _logout(BuildContext context, WidgetRef ref) async {
     // api.logout 尽力而为（服务端撤销失败也照常本地清会话——客户端内已处理）。
     await ref.read(apiClientProvider).logout();
+    // 会话账号失效 → 引擎 stop（任务保留库内，见 engine_scope.dart）。
+    await ref.read(sessionAccountProvider.notifier).refresh();
     if (!context.mounted) return;
     Navigator.of(context).pushNamedAndRemoveUntil('/login', (route) => false);
   }