新增：体重录入与历史列表接入真实数据（T2-13 体重半边）

- WeightRecordsPage：cursor 分页（加载更多/末页收起/翻页失败保留重试）、
  loading/empty/error/retry 四态、下拉刷新；viewer 隐藏录入入口
- WeightFormPage：weightKg 契约区间 (0,500] 与两位小数前端校验 + 40000
  兜底；称重时间转 UTC 上送；错误三层分层沿用登录纵切
- health_record 域埋点强类型封装（06 §1.4：create_started/succeeded/
  failed + viewed，httpStatus 由业务码推导；viewed 按工单口径取列表曝光）
- health_record_display 纯函数（体重解析/展示、疫苗状态映射、42201
  规则前端拦截函数）；PetsController 暴露 repository（22 号 §7 交接）
- 测试 177 → 205（+28）全绿

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/helpers/pet_test_helpers.dart

@@ -129,6 +129,44 @@ Pet buildPet(
   ),
 );
 
+Map<String, dynamic> sampleVaccineCatalogJson({
+  String id = 'v-1',
+  String code = 'rabies',
+  String name = '狂犬疫苗',
+  String species = 'dog',
+}) => {
+  'id': id,
+  'code': code,
+  'name': name,
+  'species': species,
+  'description': null,
+};
+
+/// 快速构造体重记录（widget 测试共用）。
+WeightRecord buildWeight(
+  String id, {
+  double weightKg = 4.35,
+  String measuredAt = '2026-09-07T09:00:00+08:00',
+  Map<String, Object?> overrides = const {},
+}) => WeightRecord.fromJson({
+  ...sampleWeightJson(),
+  'id': id,
+  'weightKg': weightKg,
+  'measuredAt': measuredAt,
+  ...overrides,
+});
+
+/// 快速构造疫苗记录。
+Vaccination buildVaccination(
+  String id, {
+  Map<String, Object?> overrides = const {},
+}) =>
+    Vaccination.fromJson({...sampleVaccinationJson(), 'id': id, ...overrides});
+
+/// 快速构造摘要（缺省为「三聚合齐备」样本；overrides 可置 null 验证空态）。
+PetSummary buildSummary({Map<String, Object?> overrides = const {}}) =>
+    PetSummary.fromJson({...samplePetSummaryJson(), ...overrides});
+
 /// 假仓库：各方法可注入行为；listPets 默认空列表，其余未注入的方法抛
 /// UnimplementedError（22 号报告 §7：widget 测试注入假仓库的共享实现）。
 class FakePetsRepository implements PetsRepository {
@@ -137,6 +175,16 @@ class FakePetsRepository implements PetsRepository {
   Future<Pet> Function(String)? getPetHandler;
   Future<Pet> Function(String, UpdatePetRequest)? updatePetHandler;
   Future<List<Breed>> Function(PetSpecies?)? listBreedsHandler;
+  Future<CursorPage<WeightRecord>> Function(String, int?, String?)?
+  listWeightsHandler;
+  Future<WeightRecord> Function(String, CreateWeightRequest)?
+  createWeightHandler;
+  Future<List<VaccineCatalogItem>> Function(PetSpecies?)?
+  listVaccineCatalogHandler;
+  Future<List<Vaccination>> Function(String)? listVaccinationsHandler;
+  Future<Vaccination> Function(String, CreateVaccinationRequest)?
+  createVaccinationHandler;
+  Future<PetSummary> Function(String, String?)? getPetSummaryHandler;
 
   @override
   Future<List<Pet>> listPets() =>
@@ -157,6 +205,53 @@ class FakePetsRepository implements PetsRepository {
       listBreedsHandler?.call(species) ??
       Future.value([Breed.fromJson(sampleBreedJson())]);
 
+  @override
+  Future<CursorPage<WeightRecord>> listWeights(
+    String petId, {
+    int? limit,
+    String? cursor,
+  }) => listWeightsHandler!(petId, limit, cursor);
+
+  @override
+  Future<WeightRecord> createWeight(
+    String petId,
+    CreateWeightRequest request,
+  ) => createWeightHandler!(petId, request);
+
+  @override
+  Future<List<VaccineCatalogItem>> listVaccineCatalog({PetSpecies? species}) =>
+      listVaccineCatalogHandler?.call(species) ??
+      Future.value([VaccineCatalogItem.fromJson(sampleVaccineCatalogJson())]);
+
+  @override
+  Future<List<Vaccination>> listVaccinations(String petId) =>
+      listVaccinationsHandler!(petId);
+
+  @override
+  Future<Vaccination> createVaccination(
+    String petId,
+    CreateVaccinationRequest request,
+  ) => createVaccinationHandler!(petId, request);
+
+  @override
+  Future<PetSummary> getPetSummary(String petId, {String? tz}) =>
+      getPetSummaryHandler?.call(petId, tz) ??
+      // 缺省给「无任何记录」空摘要（契约 null 语义），既有详情页测试
+      // 不必逐个注入。
+      Future.value(
+        PetSummary.fromJson({
+          'petId': petId,
+          'latestWeight': null,
+          'vaccinationProgress': null,
+          'nextVaccination': null,
+          'monthlyExpense': {
+            'month': '2026-09',
+            'timezone': 'UTC',
+            'amountCents': 0,
+          },
+        }),
+      );
+
   @override
   dynamic noSuchMethod(Invocation invocation) =>
       throw UnimplementedError('${invocation.memberName}');