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/models/finance.dart

@@ -0,0 +1,52 @@
+class FinanceRecord {
+  final int id;
+  final String type; // receivable | payable | receipt | payment
+  final double amount;
+  final double balance;
+  final String? refType;
+  final int? refId;
+  final String? partnerName;
+  final String? recordDate;
+  final String? remark;
+
+  const FinanceRecord({
+    required this.id,
+    required this.type,
+    required this.amount,
+    required this.balance,
+    this.refType,
+    this.refId,
+    this.partnerName,
+    this.recordDate,
+    this.remark,
+  });
+
+  String get typeLabel {
+    switch (type) {
+      case 'receivable':
+        return '应收账款';
+      case 'payable':
+        return '应付账款';
+      case 'receipt':
+        return '收款';
+      case 'payment':
+        return '付款';
+      default:
+        return type;
+    }
+  }
+
+  factory FinanceRecord.fromJson(Map<String, dynamic> json) => FinanceRecord(
+        id: (json['id'] as num).toInt(),
+        type: json['type'] as String,
+        amount: (json['amount'] as num).toDouble(),
+        balance: (json['balance'] as num).toDouble(),
+        refType: json['ref_type'] as String?,
+        refId:
+            json['ref_id'] != null ? (json['ref_id'] as num).toInt() : null,
+        partnerName:
+            (json['partner'] as Map<String, dynamic>?)?['name'] as String?,
+        recordDate: json['record_date'] as String?,
+        remark: json['remark'] as String?,
+      );
+}

client/lib/models/inventory.dart

@@ -43,6 +43,61 @@ class Inventory {
   }
 }
 
+// 批次追踪：已审核入库单的明细行
+class BatchRecord {
+  final int id;
+  final int productId;
+  final String? productName;
+  final String? productCode;
+  final String? productSpec;
+  final String? productUnit;
+  final String? batchNo;
+  final double quantity;
+  final double unitPrice;
+  final String? orderNo;
+  final String? orderDate;
+  final String? warehouseName;
+  final String? supplierName;
+
+  const BatchRecord({
+    required this.id,
+    required this.productId,
+    this.productName,
+    this.productCode,
+    this.productSpec,
+    this.productUnit,
+    this.batchNo,
+    required this.quantity,
+    required this.unitPrice,
+    this.orderNo,
+    this.orderDate,
+    this.warehouseName,
+    this.supplierName,
+  });
+
+  factory BatchRecord.fromJson(Map<String, dynamic> json) {
+    final product = json['product'] as Map<String, dynamic>?;
+    final order = json['order'] as Map<String, dynamic>?;
+    final warehouse = order?['warehouse'] as Map<String, dynamic>?;
+    final partner = order?['partner'] as Map<String, dynamic>?;
+    return BatchRecord(
+      id: (json['id'] as num).toInt(),
+      productId: (json['product_id'] as num).toInt(),
+      productName: product?['name'] as String?,
+      productCode: product?['code'] as String?,
+      productSpec: product?['spec'] as String?,
+      productUnit: product?['unit'] as String?,
+      batchNo: json['batch_no'] as String?,
+      quantity: (json['quantity'] as num).toDouble(),
+      unitPrice: (json['unit_price'] as num).toDouble(),
+      orderNo: order?['order_no'] as String?,
+      orderDate: order?['order_date'] as String?,
+      warehouseName: warehouse?['name'] as String?,
+      supplierName: partner?['name'] as String?,
+    );
+  }
+}
+
 class InventoryLog {
   final int warehouseId;
   final String? warehouseName;

client/lib/models/number_rule.dart

@@ -0,0 +1,44 @@
+class NumberRule {
+  final int id;
+  final String type;
+  final String prefix;
+  final int currentNo;
+  final String dateFormat;
+
+  const NumberRule({
+    required this.id,
+    required this.type,
+    required this.prefix,
+    required this.currentNo,
+    required this.dateFormat,
+  });
+
+  String get typeLabel {
+    switch (type) {
+      case 'stock_in':
+        return '入库单';
+      case 'stock_out':
+        return '出库单';
+      case 'inventory_check':
+        return '盘点单';
+      case 'product':
+        return '商品编码';
+      default:
+        return type;
+    }
+  }
+
+  String get exampleNo {
+    final now = DateTime.now();
+    final date = '${now.year}${now.month.toString().padLeft(2, '0')}${now.day.toString().padLeft(2, '0')}';
+    return '$prefix$date${(currentNo + 1).toString().padLeft(3, '0')}';
+  }
+
+  factory NumberRule.fromJson(Map<String, dynamic> json) => NumberRule(
+        id: (json['id'] as num).toInt(),
+        type: json['type'] as String,
+        prefix: json['prefix'] as String? ?? '',
+        currentNo: (json['current_no'] as num).toInt(),
+        dateFormat: json['date_format'] as String? ?? 'YYYYMMDD',
+      );
+}

client/lib/models/stock_in.dart

@@ -33,10 +33,10 @@ class StockInItem {
         unitPrice: (json['unit_price'] as num).toDouble(),
         totalPrice: (json['total_price'] as num).toDouble(),
         batchNo: json['batch_no'] as String?,
-        productName: json['product_name'] as String?,
-        productCode: json['product_code'] as String?,
-        productSpec: json['product_spec'] as String?,
-        productUnit: json['product_unit'] as String?,
+        productName: (json['product'] as Map<String, dynamic>?)?['name'] as String?,
+        productCode: (json['product'] as Map<String, dynamic>?)?['code'] as String?,
+        productSpec: (json['product'] as Map<String, dynamic>?)?['spec'] as String?,
+        productUnit: (json['product'] as Map<String, dynamic>?)?['unit'] as String?,
       );
 
   Map<String, dynamic> toJson() => {

client/lib/models/stock_out.dart

@@ -29,10 +29,10 @@ class StockOutItem {
         quantity: (json['quantity'] as num).toDouble(),
         unitPrice: (json['unit_price'] as num).toDouble(),
         totalPrice: (json['total_price'] as num).toDouble(),
-        productName: json['product_name'] as String?,
-        productCode: json['product_code'] as String?,
-        productSpec: json['product_spec'] as String?,
-        productUnit: json['product_unit'] as String?,
+        productName: (json['product'] as Map<String, dynamic>?)?['name'] as String?,
+        productCode: (json['product'] as Map<String, dynamic>?)?['code'] as String?,
+        productSpec: (json['product'] as Map<String, dynamic>?)?['spec'] as String?,
+        productUnit: (json['product'] as Map<String, dynamic>?)?['unit'] as String?,
       );
 }