feat(app): wire server dedup - force passthrough + PHOTO_DUPLICATE classification & l10n

Task 8: close the gap between server-side duplicate detection (90dcc58)
and the app.

- ApiClient.mapDioException: normalize 409 wire body reusing
  VALIDATION_FAILED with message=PHOTO_DUPLICATE to
  ErrorCodes.photoDuplicate (message-based; auto-compat if the contract
  later adds a dedicated code)
- l10n zh/en errorPhotoDuplicate; error_l10n maps the code (queue page
  inherits via fallback)
- UploadEngine._classifyFailure: PHOTO_DUPLICATE joins the no-auto-retry
  bucket (retrying the same init body would 409 again); force to skip
  dedup travels only through the enqueue path
- UploadTasks drift table +force column (schema v2, addColumn migration;
  legacy rows default false); UploadTaskDraft/UploadTask/prepare carry it
- enqueueForUpload +forcePaths; duplicate dialog "全部上传" (capture page
  + album detail page) now returns DuplicateDialogChoice so confirmed
  duplicates enqueue with force=true (server adjudicates owner/admin)
- engine init body carries force only when true (absent otherwise)

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

apps/mobile/test/pages/capture_page_test.dart

@@ -405,6 +405,63 @@ void main() {
     expect(await store.listByAccount('alice'), hasLength(2));
   });
 
+  testWidgets('查重弹窗「全部上传」→ 重复项 force 入队、非重复项正常（Task 8）',
+      (tester) async {
+    // 既有已完成任务：与 pick1 同名同字节（本地查重命中一张）。
+    final seed = await store.create(UploadTaskDraft(
+      id: 'task-dup-seed',
+      accountId: 'alice',
+      albumId: 'alb-1',
+      clientTaskId: 'ct-dup-seed',
+      sourceFilePath: '${tmp.path}/seed-dup.jpg',
+      filename: 'pick1.jpg',
+      bytes: kJpgBytes.length,
+      contentType: 'image/jpeg',
+    ));
+    for (final state in [
+      UploadTaskState.queued,
+      UploadTaskState.uploading,
+      UploadTaskState.uploadedConfirming,
+      UploadTaskState.completed,
+    ]) {
+      await store.updateState(seed.id, state);
+    }
+
+    final pick1 = File('${tmp.path}/pick1.jpg')..writeAsBytesSync(kJpgBytes);
+    final pick2 = File('${tmp.path}/pick2.jpg')..writeAsBytesSync(kJpgBytes);
+    galleryPaths.addAll([pick1.path, pick2.path]);
+    await pumpCapture(tester);
+
+    // 相册入口：真实 IO 区完成查重，随后弹窗挂起等待选择。
+    await pressRealIo(tester, Icons.photo_library_outlined);
+    await tester.pump(const Duration(milliseconds: 300));
+    expect(find.text('可能已上传过'), findsOneWidget, reason: '查重弹窗出现');
+
+    // 「全部上传」= 用户确认强传：重复项 force=true、非重复项不受影响。
+    await tester.tap(find.text('全部上传 2 张'));
+    await tester.pump(const Duration(milliseconds: 100));
+    // 入队复制走真实文件 IO：真实事件循环窗口内完成。
+    await tester.runAsync(() async {
+      await Future<void>.delayed(const Duration(milliseconds: 300));
+    });
+    await tester.pumpAndSettle();
+
+    expect(find.text('Added 2 photo(s) to the upload queue'), findsOneWidget);
+    final tasks = await store.listByAccount('alice');
+    final fresh = tasks.where((t) => t.id != seed.id).toList();
+    expect(fresh, hasLength(2));
+    expect(
+      fresh.firstWhere((t) => t.filename == 'pick1.jpg').force,
+      isTrue,
+      reason: '重复项经「全部上传」确认强传',
+    );
+    expect(
+      fresh.firstWhere((t) => t.filename == 'pick2.jpg').force,
+      isFalse,
+      reason: '非重复项正常查重语义',
+    );
+  });
+
   testWidgets('退出确认：有待传任务 → 弹确认；保留继续拍 / 确认才退出',
       (tester) async {
     await pumpCapture(tester);