feat: 新增用户自助注册功能

后端新增 POST /api/v1/public/register 接口，支持门店自助注册并自动生成门店编码（S000001 格式）；shops 表加 description 字段。营销站新增 /register/ 注册页，含门店信息和管理员账号表单，注册成功后展示门店编码和登录提示。Flutter 登录页底部加「前往官网注册」跳转链接。

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

backend/internal/handler/auth.go

@@ -49,6 +49,23 @@ func (h *AuthHandler) Login(c *gin.Context) {
 	})
 }
 
+// Register POST /api/v1/public/register
+func (h *AuthHandler) Register(c *gin.Context) {
+	var req service.RegisterInput
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	result, err := h.svc.Register(req)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{"data": result})
+}
+
 // Refresh POST /api/v1/auth/refresh
 func (h *AuthHandler) Refresh(c *gin.Context) {
 	var req struct {

backend/internal/model/shop.go

@@ -4,6 +4,7 @@ type Shop struct {
 	Base
 	Name            string `gorm:"size:100;not null" json:"name"`
 	Code            string `gorm:"size:50;uniqueIndex" json:"code"`
+	Description     string `gorm:"type:text" json:"description"`
 	Address         string `gorm:"size:255" json:"address"`
 	Phone           string `gorm:"size:30" json:"phone"`
 	BusinessHours   string `gorm:"size:100" json:"business_hours"`

backend/internal/router/router.go

@@ -58,6 +58,7 @@ func Setup(r *gin.Engine, db *gorm.DB) {
 		public.GET("/products/:public_id", publicH.GetProduct)
 		public.GET("/release", publicH.GetRelease)
 		public.POST("/errors", errorReportH.Submit)
+		public.POST("/register", authH.Register)
 	}
 
 	// 需要 JWT 的路由（ReadOnly 中间件：只读用户不可执行写操作）

backend/internal/service/auth.go

@@ -2,9 +2,11 @@ package service
 
 import (
 	"errors"
+	"fmt"
 	"time"
 
 	"github.com/golang-jwt/jwt/v5"
+	"github.com/google/uuid"
 	"golang.org/x/crypto/bcrypt"
 	"gorm.io/gorm"
 
@@ -61,6 +63,76 @@ func (s *AuthService) Login(shopCode, username, password string) (*TokenPair, *m
 	return pair, &user, nil
 }
 
+// RegisterInput 注册新门店所需参数
+type RegisterInput struct {
+	ShopName    string `json:"shop_name"    binding:"required"`
+	Address     string `json:"address"      binding:"required"`
+	ManagerName string `json:"manager_name" binding:"required"`
+	Phone       string `json:"phone"        binding:"required"`
+	Description string `json:"description"`
+	Username    string `json:"username"     binding:"required"`
+	Password    string `json:"password"     binding:"required,min=6"`
+}
+
+// RegisterResult 注册成功后返回的数据
+type RegisterResult struct {
+	ShopCode string `json:"shop_code"`
+	ShopName string `json:"shop_name"`
+	Username string `json:"username"`
+}
+
+// Register 自助注册新门店（公开接口，无需认证）
+func (s *AuthService) Register(in RegisterInput) (*RegisterResult, error) {
+	hash, err := bcrypt.GenerateFromPassword([]byte(in.Password), bcrypt.DefaultCost)
+	if err != nil {
+		return nil, err
+	}
+
+	var result RegisterResult
+	err = s.db.Transaction(func(tx *gorm.DB) error {
+		// 先用 UUID 占位创建门店，得到真实 ID
+		shop := model.Shop{
+			Name:        in.ShopName,
+			Code:        uuid.New().String(),
+			Address:     in.Address,
+			Phone:       in.Phone,
+			ManagerName: in.ManagerName,
+			Description: in.Description,
+		}
+		if err := tx.Create(&shop).Error; err != nil {
+			return err
+		}
+
+		// 用自增 ID 生成正式门店编码
+		shop.Code = fmt.Sprintf("S%06d", shop.ID)
+		if err := tx.Model(&shop).Update("code", shop.Code).Error; err != nil {
+			return err
+		}
+
+		// 创建管理员用户
+		user := model.User{
+			ShopID:       shop.ID,
+			Username:     in.Username,
+			PasswordHash: string(hash),
+			RealName:     in.ManagerName,
+			Phone:        in.Phone,
+			Role:         "admin",
+			IsActive:     true,
+		}
+		if err := tx.Create(&user).Error; err != nil {
+			return err
+		}
+
+		result = RegisterResult{
+			ShopCode: shop.Code,
+			ShopName: shop.Name,
+			Username: user.Username,
+		}
+		return nil
+	})
+	return &result, err
+}
+
 // HashPassword 生成 bcrypt 哈希
 func HashPassword(plain string) (string, error) {
 	b, err := bcrypt.GenerateFromPassword([]byte(plain), bcrypt.DefaultCost)

backend/schema/schema.sql

@@ -17,6 +17,7 @@ CREATE TABLE IF NOT EXISTS `shops` (
   `address`          VARCHAR(255)    DEFAULT NULL,
   `phone`            VARCHAR(30)     DEFAULT NULL,
   `manager_name`     VARCHAR(50)     DEFAULT NULL COMMENT '负责人',
+  `description`      TEXT            DEFAULT NULL COMMENT '店铺简介',
   `logo_url`         VARCHAR(500)    DEFAULT ''   COMMENT '门店 logo URL',
   `business_license` VARCHAR(500)    DEFAULT NULL COMMENT '营业执照照片URL',
   `shop_photos`      JSON            DEFAULT NULL COMMENT '门店照片URL数组',

backend/testutil/setup.go

@@ -53,6 +53,7 @@ func SetupTestDB() *gorm.DB {
 			deleted_at DATETIME,
 			name TEXT NOT NULL,
 			code TEXT UNIQUE,
+			description TEXT,
 			address TEXT,
 			phone TEXT,
 			manager_name TEXT,