feat: 完成7项功能任务

后端：
- fix(backend): InventoryLog 增加 Product/Warehouse 关联，Logs 接口加 Preload 修复流水记录显示"-"
- feat(backend): 新增 /inventory/batches 批次追踪接口
- feat(backend): 新增财务记录、编号规则接口（finance、number_rule handler）
- fix(backend): service/stock_test.go 修复 model.Date 类型错误

前端：
- feat(client): 入库/出库管理 Tab 调换顺序（审核在前），审核 Tab 加新建按钮，列表 Tab 无按钮
- feat(client): 入库单/出库单增加详情弹窗，显示完整单据信息和商品明细
- feat(client): 完善出库单新建表单（StockOutFormScreen），支持选客户/仓库/商品
- fix(client): StockInItem/StockOutItem.fromJson 修复读取嵌套 product 对象而非平铺字段
- feat(client): 批次追踪页面（BatchTrackingScreen）及侧边栏入口
- feat(client): 财务管理、盘点、编号规则接入真实后端 API
- fix(client): 入库/出库审核通过后 invalidate inventoryListProvider 刷新库存

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/lib/providers/finance_provider.dart

@@ -0,0 +1,60 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../core/api/api_client.dart';
+import '../core/auth/auth_state.dart';
+import '../core/models/page_result.dart';
+import '../models/finance.dart';
+import '../repositories/finance_repository.dart';
+
+final financeRepositoryProvider = Provider<FinanceRepository>((ref) {
+  return FinanceRepository(ref.watch(apiClientProvider));
+});
+
+final financeListProvider =
+    AsyncNotifierProvider<FinanceListNotifier, PageResult<FinanceRecord>>(
+  FinanceListNotifier.new,
+);
+
+class FinanceListNotifier extends AsyncNotifier<PageResult<FinanceRecord>> {
+  int _page = 1;
+  String _type = '';
+  String _month = '';
+
+  @override
+  Future<PageResult<FinanceRecord>> build() {
+    ref.watch(authStateProvider.select((s) => s.user?.shopId));
+    return _fetch();
+  }
+
+  Future<PageResult<FinanceRecord>> _fetch() {
+    return ref.read(financeRepositoryProvider).listRecords(
+          type: _type.isEmpty ? null : _type,
+          month: _month.isEmpty ? null : _month,
+          page: _page,
+        );
+  }
+
+  void setType(String type) {
+    _type = type;
+    _page = 1;
+    reload();
+  }
+
+  void setMonth(String month) {
+    _month = month;
+    _page = 1;
+    reload();
+  }
+
+  void setPage(int page) {
+    _page = page;
+    reload();
+  }
+
+  void reload() {
+    state = const AsyncValue.loading();
+    _fetch().then(
+      (result) => state = AsyncValue.data(result),
+      onError: (e, st) => state = AsyncValue.error(e, st),
+    );
+  }
+}

client/lib/providers/number_rule_provider.dart

@@ -0,0 +1,33 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../core/api/api_client.dart';
+import '../core/auth/auth_state.dart';
+import '../models/number_rule.dart';
+import '../repositories/number_rule_repository.dart';
+
+final numberRuleRepositoryProvider = Provider<NumberRuleRepository>((ref) {
+  return NumberRuleRepository(ref.watch(apiClientProvider));
+});
+
+final numberRuleListProvider =
+    AsyncNotifierProvider<NumberRuleListNotifier, List<NumberRule>>(
+  NumberRuleListNotifier.new,
+);
+
+class NumberRuleListNotifier extends AsyncNotifier<List<NumberRule>> {
+  @override
+  Future<List<NumberRule>> build() {
+    ref.watch(authStateProvider.select((s) => s.user?.shopId));
+    return ref.read(numberRuleRepositoryProvider).list();
+  }
+
+  Future<void> reload() async {
+    state = const AsyncValue.loading();
+    state = await AsyncValue.guard(
+        () => ref.read(numberRuleRepositoryProvider).list());
+  }
+
+  Future<void> updateRule(int id, Map<String, dynamic> data) async {
+    await ref.read(numberRuleRepositoryProvider).update(id, data);
+    await reload();
+  }
+}

client/lib/providers/stock_in_provider.dart

@@ -4,6 +4,7 @@ import '../core/auth/auth_state.dart';
 import '../core/models/page_result.dart';
 import '../models/stock_in.dart';
 import '../repositories/stock_in_repository.dart';
+import 'inventory_provider.dart';
 
 final stockInRepositoryProvider = Provider<StockInRepository>((ref) {
   return StockInRepository(ref.watch(apiClientProvider));
@@ -74,6 +75,7 @@ class StockInListNotifier extends AsyncNotifier<PageResult<StockInOrder>> {
   Future<void> approveOrder(int id) async {
     await ref.read(stockInRepositoryProvider).approve(id);
     reload();
+    ref.invalidate(inventoryListProvider);
   }
 
   Future<void> rejectOrder(int id) async {

client/lib/providers/stock_out_provider.dart

@@ -4,6 +4,7 @@ import '../core/auth/auth_state.dart';
 import '../core/models/page_result.dart';
 import '../models/stock_out.dart';
 import '../repositories/stock_out_repository.dart';
+import 'inventory_provider.dart';
 
 final stockOutRepositoryProvider = Provider<StockOutRepository>((ref) {
   return StockOutRepository(ref.watch(apiClientProvider));
@@ -74,6 +75,7 @@ class StockOutListNotifier extends AsyncNotifier<PageResult<StockOutOrder>> {
   Future<void> approveOrder(int id) async {
     await ref.read(stockOutRepositoryProvider).approve(id);
     reload();
+    ref.invalidate(inventoryListProvider);
   }
 
   Future<void> rejectOrder(int id) async {