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>

backend/internal/handler/finance.go

@@ -0,0 +1,63 @@
+package handler
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+
+	"github.com/wangjia/jiu/backend/internal/middleware"
+	"github.com/wangjia/jiu/backend/internal/model"
+)
+
+type FinanceHandler struct {
+	db *gorm.DB
+}
+
+func NewFinanceHandler(db *gorm.DB) *FinanceHandler {
+	return &FinanceHandler{db: db}
+}
+
+// ListRecords GET /api/v1/finance/records
+func (h *FinanceHandler) ListRecords(c *gin.Context) {
+	shopID := middleware.GetShopID(c)
+
+	var q struct {
+		Type     string `form:"type"`
+		Month    string `form:"month"` // e.g. "2026-04"
+		Page     int    `form:"page,default=1"`
+		PageSize int    `form:"page_size,default=50"`
+	}
+	if err := c.ShouldBindQuery(&q); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	if q.PageSize <= 0 {
+		q.PageSize = 50
+	}
+	if q.Page <= 0 {
+		q.Page = 1
+	}
+
+	base := h.db.Model(&model.FinanceRecord{}).Where("shop_id = ?", shopID)
+	if q.Type != "" {
+		base = base.Where("type = ?", q.Type)
+	}
+	if q.Month != "" {
+		base = base.Where("DATE_FORMAT(record_date, '%Y-%m') = ?", q.Month)
+	}
+
+	var total int64
+	base.Count(&total)
+
+	var records []model.FinanceRecord
+	offset := (q.Page - 1) * q.PageSize
+	base.Preload("Partner").Order("record_date DESC, id DESC").Offset(offset).Limit(q.PageSize).Find(&records)
+
+	c.JSON(http.StatusOK, gin.H{
+		"data":      records,
+		"total":     total,
+		"page":      q.Page,
+		"page_size": q.PageSize,
+	})
+}