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/features/uploads/upload_engine_test.dart

@@ -71,6 +71,10 @@ class Harness {
   int initNetworkFailures = 0;
   int initUnauthorized = 0;
   int initAlbumDisabled = 0;
+
+  /// initUpload 查重 409 次数（Task 8：wire 体复用 VALIDATION_FAILED code、
+  /// message=PHOTO_DUPLICATE）。
+  int initDuplicateRejects = 0;
   int completeVerifyFailures = 0;
   int completeNetworkFailures = 0;
   int putNetworkFailures = 0;
@@ -124,6 +128,19 @@ class Harness {
         initAlbumDisabled--;
         return (409, errorBody(ErrorCodes.albumUploadDisabled));
       }
+      if (initDuplicateRejects > 0) {
+        initDuplicateRejects--;
+        // P0-1 契约现状：查重拒绝 409 的 code 复用 VALIDATION_FAILED，
+        // 靠 message=PHOTO_DUPLICATE 识别（Task 8 客户端归一依据）。
+        return (
+          409,
+          <String, dynamic>{
+            'code': ErrorCodes.validationFailed,
+            'message': 'PHOTO_DUPLICATE',
+            'requestId': 'req-dup',
+          },
+        );
+      }
       if (initUnauthorized > 0) {
         initUnauthorized--;
         return (401, errorBody(ErrorCodes.authTokenExpired));
@@ -218,6 +235,7 @@ class Harness {
     String? categoryId,
     String clientTaskId = 'ct-default',
     DateTime? createdAt,
+    bool force = false,
   }) async {
     final draft = UploadTaskDraft(
       id: 'task-$clientTaskId',
@@ -229,6 +247,7 @@ class Harness {
       filename: file.uri.pathSegments.last,
       bytes: await file.length(),
       contentType: 'image/jpeg',
+      force: force,
     );
     final task = await store.create(draft, now: createdAt);
     return store.updateState(
@@ -399,6 +418,8 @@ void main() {
       expect(body['bytes'], 1024);
       expect(body['contentType'], 'image/jpeg');
       expect(body['sourceDeviceId'], _kDeviceId);
+      expect(body.containsKey('force'), isFalse,
+          reason: '非强传任务不下发 force（缺省语义）');
 
       // PUT：预签名 URL + 凭证头 + Content-Length；无 Authorization
       // （裸 Dio——Bearer 会破坏 MinIO 预签名）。
@@ -417,6 +438,24 @@ void main() {
       expect(progress[seeded.id]?.last, 1024);
     });
 
+    test('force 任务：init 请求体携带 force:true（Task 8 查重强传透传）',
+        () async {
+      final file = photoFile('force-1.jpg');
+      engine = h.buildEngine();
+      engine.start('alice', period: const Duration(hours: 1));
+
+      final seeded = await h.seedTask(
+        file,
+        clientTaskId: 'ct-force-1',
+        force: true,
+      );
+      await cycle();
+
+      expect((await task(seeded.id)).state, UploadTaskState.completed);
+      expect(h.initBodies.single['force'], isTrue,
+          reason: '弹窗「全部上传」确认的强传必须到达服务端');
+    });
+
     test('与准备器集成：preparing → queued → completed（受管副本上传）',
         () async {
       final src = photoFile('src.jpg');
@@ -621,6 +660,31 @@ void main() {
       expect(h.initBodies.length, initCount, reason: '无自动重试');
     });
 
+    test('409 PHOTO_DUPLICATE（服务端查重拒绝）→ retryableFailed 不自动重试',
+        () async {
+      final file = photoFile('dup.jpg');
+      engine = h.buildEngine();
+      engine.start('alice', period: const Duration(hours: 1));
+      h.initDuplicateRejects = 99; // 永远 409（重试同样被拒）。
+
+      final seeded = await h.seedTask(file, clientTaskId: 'ct-dup');
+      await cycle();
+
+      final t = await task(seeded.id);
+      expect(t.state, UploadTaskState.retryableFailed);
+      // 归一后 lastError=PHOTO_DUPLICATE（此前缺陷：VALIDATION_FAILED 落
+      // 桶 4 自动重试，文案误导）。
+      expect(t.lastError, ErrorCodes.photoDuplicate);
+      expect(t.nextRetryAt, isNull, reason: '重试必然再 409：不自动重试');
+      expect(t.attempt, 0, reason: '客户端重试无意义，不烧次数');
+
+      final initCount = h.initBodies.length;
+      h.clock = h.clock.add(const Duration(hours: 1));
+      await cycle();
+      expect(h.initBodies.length, initCount,
+          reason: '无自动重试（单次 init 即终判）');
+    });
+
     test('401 会话过期 → waitingNetwork 短退避；重登录后（重试）完成，'
         'attempt 不增长', () async {
       final file = photoFile('g.jpg');