feat: PhotoWall 毕业照存储系统初始版本

后端: Go(Gin+GORM+MySQL+Redis)
- 17张业务表(yz_pw_前缀), 自动迁移
- JWT认证(3小时) + 盐+MD5密码 + 图形验证码
- 班级CRUD/加入(8人姓名验证/邀请码)/审核/30天自动清理
- 系统配置(16项)/菜单管理(动态路由)/数据统计
- 文件MD5去重/数据隔离/账号封禁/敏感词DFA检测

前端: Vue3+Vite+Element Plus+Less+ECharts+FontAwesome
- 动态路由(数据库菜单驱动)
- 蓝白配色, H5响应式
- 登录/注册/忘记密码/个人中心
- 班级创建向导/详情/加入/列表
- 管理后台: 审核/配置/菜单/统计/用户/敏感词

数据库: MySQL 10.31.100.3:3306/photowall
管理员: hero920103 / 920103

go/internal/service/school_service.go

@@ -0,0 +1,155 @@
+package service
+
+import (
+	"errors"
+	"photowall/internal/model"
+
+	"gorm.io/gorm"
+)
+
+type SchoolService struct {
+	db *gorm.DB
+}
+
+func NewSchoolService(db *gorm.DB) *SchoolService {
+	return &SchoolService{db: db}
+}
+
+type SchoolQuery struct {
+	RegionID   uint             `form:"region_id"`
+	SchoolType model.SchoolType `form:"school_type"`
+	Keyword    string           `form:"keyword"`
+	Page       int              `form:"page"`
+	PageSize   int              `form:"page_size"`
+}
+
+// PageResp 通用分页响应
+type PageResp struct {
+	List  interface{} `json:"list"`
+	Total int64       `json:"total"`
+	Page  int         `json:"page"`
+}
+
+type SchoolListResp = PageResp // 别名兼容
+
+func (s *SchoolService) List(q *SchoolQuery) (*SchoolListResp, error) {
+	if q.Page <= 0 {
+		q.Page = 1
+	}
+	if q.PageSize <= 0 || q.PageSize > 100 {
+		q.PageSize = 20
+	}
+	db := s.db.Model(&model.School{})
+	if q.RegionID > 0 {
+		db = db.Where("region_id = ?", q.RegionID)
+	}
+	if q.SchoolType != "" {
+		db = db.Where("school_type = ?", q.SchoolType)
+	}
+	if q.Keyword != "" {
+		db = db.Where("name LIKE ? OR name_en LIKE ?", "%"+q.Keyword+"%", "%"+q.Keyword+"%")
+	}
+	var total int64
+	db.Count(&total)
+	var list []model.School
+	err := db.Order("id desc").Offset((q.Page - 1) * q.PageSize).Limit(q.PageSize).Find(&list).Error
+	if err != nil {
+		return nil, err
+	}
+	return &SchoolListResp{List: list, Total: total, Page: q.Page}, nil
+}
+
+// Create 创建学校（必须挂在 county 级地区下）
+func (s *SchoolService) Create(school *model.School) error {
+	// 校验 region 必须是 county 级
+	var region model.Region
+	if err := s.db.First(&region, school.RegionID).Error; err != nil {
+		return errors.New("所属地区不存在")
+	}
+	if region.Level != model.LevelCounty {
+		return errors.New("学校必须挂载在区/县级地区下")
+	}
+	if school.Name == "" {
+		return errors.New("学校名称不能为空")
+	}
+	if school.SchoolType == "" {
+		return errors.New("请选择学校类型")
+	}
+	return s.db.Create(school).Error
+}
+
+func (s *SchoolService) GetByID(id uint) (*model.School, error) {
+	var school model.School
+	if err := s.db.First(&school, id).Error; err != nil {
+		return nil, errors.New("学校不存在")
+	}
+	return &school, nil
+}
+
+func (s *SchoolService) Update(id uint, updates map[string]interface{}) error {
+	res := s.db.Model(&model.School{}).Where("id = ?", id).Updates(updates)
+	if res.Error != nil {
+		return res.Error
+	}
+	if res.RowsAffected == 0 {
+		return errors.New("学校不存在")
+	}
+	return nil
+}
+
+func (s *SchoolService) Delete(id uint) error {
+	// 检查是否有班级引用
+	var count int64
+	s.db.Model(&model.Class{}).Where("school_id = ?", id).Count(&count)
+	if count > 0 {
+		return errors.New("该学校下已有班级，无法删除")
+	}
+	return s.db.Delete(&model.School{}, id).Error
+}
+
+// ---- 学院 ----
+
+func (s *SchoolService) ListColleges(schoolID uint) ([]model.College, error) {
+	var list []model.College
+	err := s.db.Where("school_id = ?", schoolID).Order("name").Find(&list).Error
+	return list, err
+}
+
+func (s *SchoolService) CreateCollege(schoolID uint, name string) (*model.College, error) {
+	if name == "" {
+		return nil, errors.New("学院名称不能为空")
+	}
+	// 校验学校是否支持学院
+	var school model.School
+	if err := s.db.First(&school, schoolID).Error; err != nil {
+		return nil, errors.New("学校不存在")
+	}
+	if !school.SchoolType.HasCollege() {
+		return nil, errors.New("该学校类型不支持学院层级")
+	}
+	c := &model.College{SchoolID: schoolID, Name: name}
+	if err := s.db.Create(c).Error; err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+func (s *SchoolService) UpdateCollege(id uint, name string) error {
+	res := s.db.Model(&model.College{}).Where("id = ?", id).Update("name", name)
+	if res.Error != nil {
+		return res.Error
+	}
+	if res.RowsAffected == 0 {
+		return errors.New("学院不存在")
+	}
+	return nil
+}
+
+func (s *SchoolService) DeleteCollege(id uint) error {
+	var count int64
+	s.db.Model(&model.Class{}).Where("college_id = ?", id).Count(&count)
+	if count > 0 {
+		return errors.New("该学院下已有班级，无法删除")
+	}
+	return s.db.Delete(&model.College{}, id).Error
+}