init: 后端框架脚手架 (Go + Gin + GORM + MySQL)

- 项目目录结构：backend/ deploy/ schema/ migrations/
- 数据库 Schema：所有建表 SQL，含 hotel_id 多租户隔离
- Go 后端：config、model、handler、service、middleware、router
- 认证：账号密码登录 + JWT（Access + Refresh Token）
- 许可证：HMAC-SHA256 激活码生成 + 设备绑定验证
- 业务模块：商品、仓库、往来单位、入库、出库、库存、盘点
- 库存事务：入库/出库审核时原子更新库存 + 流水记录
- 数据导入：Excel/CSV 批量导入商品、往来单位
- Docker Compose：本地 MySQL + Adminer

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

backend/main.go

@@ -0,0 +1,104 @@
+package main
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/driver/mysql"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+
+	"github.com/wangjia/jiu/backend/config"
+	"github.com/wangjia/jiu/backend/internal/model"
+	"github.com/wangjia/jiu/backend/internal/router"
+)
+
+func main() {
+	// 加载配置
+	config.Load()
+
+	// 初始化数据库
+	db := initDB()
+
+	// 自动迁移（开发环境用，生产使用 golang-migrate）
+	if config.C.Server.Mode == "debug" {
+		autoMigrate(db)
+	}
+
+	// 启动 Gin
+	gin.SetMode(config.C.Server.Mode)
+	r := gin.New()
+	r.Use(gin.Logger(), gin.Recovery())
+
+	// CORS（开发期间允许所有来源）
+	r.Use(func(c *gin.Context) {
+		c.Header("Access-Control-Allow-Origin", "*")
+		c.Header("Access-Control-Allow-Methods", "GET,POST,PUT,DELETE,OPTIONS")
+		c.Header("Access-Control-Allow-Headers", "Authorization,Content-Type")
+		if c.Request.Method == "OPTIONS" {
+			c.AbortWithStatus(204)
+			return
+		}
+		c.Next()
+	})
+
+	router.Setup(r, db)
+
+	addr := fmt.Sprintf(":%s", config.C.Server.Port)
+	log.Printf("Server starting on %s (mode: %s)", addr, config.C.Server.Mode)
+	if err := r.Run(addr); err != nil {
+		log.Fatalf("Server failed: %v", err)
+	}
+}
+
+func initDB() *gorm.DB {
+	dsn := config.C.Database.DSN
+	if dsn == "" {
+		log.Fatal("database.dsn is required in config")
+	}
+
+	logLevel := logger.Silent
+	if config.C.Server.Mode == "debug" {
+		logLevel = logger.Info
+	}
+
+	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{
+		Logger: logger.Default.LogMode(logLevel),
+	})
+	if err != nil {
+		log.Fatalf("failed to connect database: %v", err)
+	}
+
+	sqlDB, _ := db.DB()
+	sqlDB.SetMaxIdleConns(10)
+	sqlDB.SetMaxOpenConns(100)
+	return db
+}
+
+func autoMigrate(db *gorm.DB) {
+	err := db.AutoMigrate(
+		&model.Hotel{},
+		&model.User{},
+		&model.OAuthProvider{},
+		&model.License{},
+		&model.ProductCategory{},
+		&model.Product{},
+		&model.Warehouse{},
+		&model.Partner{},
+		&model.StockInOrder{},
+		&model.StockInItem{},
+		&model.StockOutOrder{},
+		&model.StockOutItem{},
+		&model.Inventory{},
+		&model.InventoryLog{},
+		&model.InventoryCheck{},
+		&model.InventoryCheckItem{},
+		&model.FinanceRecord{},
+		&model.NumberRule{},
+	)
+	if err != nil {
+		log.Fatalf("auto migrate failed: %v", err)
+	}
+	log.Println("AutoMigrate completed")
+}