feat: 完成后端服务核心业务逻辑实现

## 主要功能
- ✅ 用户认证模块 (登录/注册/JWT)
- ✅ 照片管理模块 (上传/查询/分页/搜索)
- ✅ 分类管理模块 (创建/查询/分页)
- ✅ 用户管理模块 (用户列表/分页查询)
- ✅ 健康检查接口

## 技术实现
- 基于 go-zero v1.8.0 标准架构
- Handler → Logic → Model 三层架构
- SQLite/PostgreSQL 数据库支持
- JWT 认证机制
- bcrypt 密码加密
- 统一响应格式
- 自定义模型方法 (分页/搜索)

## API 接口
- POST /api/v1/auth/login - 用户登录
- POST /api/v1/auth/register - 用户注册
- GET /api/v1/health - 健康检查
- GET /api/v1/photos - 照片列表
- POST /api/v1/photos - 上传照片
- GET /api/v1/categories - 分类列表
- POST /api/v1/categories - 创建分类
- GET /api/v1/users - 用户列表

## 配置完成
- 开发环境配置 (SQLite)
- 生产环境支持 (PostgreSQL)
- JWT 认证配置
- 文件上传配置
- Makefile 构建脚本

服务已验证可正常构建和启动。

backend/internal/types/types.go

@@ -0,0 +1,242 @@
+// Code generated by goctl. DO NOT EDIT.
+// goctl 1.8.4
+
+package types
+
+type BaseResponse struct {
+	Code    int    `json:"code"`
+	Message string `json:"message"`
+}
+
+type Category struct {
+	Id          int64  `json:"id"`
+	Name        string `json:"name"`
+	Description string `json:"description"`
+	CreatedAt   int64  `json:"created_at"`
+	UpdatedAt   int64  `json:"updated_at"`
+}
+
+type CategoryListData struct {
+	PageResponse
+	Categories []Category `json:"categories"`
+}
+
+type CreateCategoryRequest struct {
+	Name        string `json:"name" validate:"required"`
+	Description string `json:"description,optional"`
+}
+
+type CreateCategoryResponse struct {
+	BaseResponse
+	Data Category `json:"data"`
+}
+
+type CreateUserRequest struct {
+	Username string `json:"username" validate:"required"`
+	Email    string `json:"email" validate:"required,email"`
+	Password string `json:"password" validate:"required,min=6"`
+}
+
+type CreateUserResponse struct {
+	BaseResponse
+	Data User `json:"data"`
+}
+
+type DeleteCategoryRequest struct {
+	Id int64 `path:"id"`
+}
+
+type DeleteCategoryResponse struct {
+	BaseResponse
+}
+
+type DeletePhotoRequest struct {
+	Id int64 `path:"id"`
+}
+
+type DeletePhotoResponse struct {
+	BaseResponse
+}
+
+type DeleteUserRequest struct {
+	Id int64 `path:"id"`
+}
+
+type DeleteUserResponse struct {
+	BaseResponse
+}
+
+type GetCategoryListRequest struct {
+	PageRequest
+	Keyword string `form:"keyword,optional"`
+}
+
+type GetCategoryListResponse struct {
+	BaseResponse
+	Data CategoryListData `json:"data"`
+}
+
+type GetCategoryRequest struct {
+	Id int64 `path:"id"`
+}
+
+type GetCategoryResponse struct {
+	BaseResponse
+	Data Category `json:"data"`
+}
+
+type GetPhotoListRequest struct {
+	PageRequest
+	CategoryId int64  `form:"category_id,optional"`
+	UserId     int64  `form:"user_id,optional"`
+	Keyword    string `form:"keyword,optional"`
+}
+
+type GetPhotoListResponse struct {
+	BaseResponse
+	Data PhotoListData `json:"data"`
+}
+
+type GetPhotoRequest struct {
+	Id int64 `path:"id"`
+}
+
+type GetPhotoResponse struct {
+	BaseResponse
+	Data Photo `json:"data"`
+}
+
+type GetUserListRequest struct {
+	PageRequest
+	Keyword string `form:"keyword,optional"`
+}
+
+type GetUserListResponse struct {
+	BaseResponse
+	Data UserListData `json:"data"`
+}
+
+type GetUserRequest struct {
+	Id int64 `path:"id"`
+}
+
+type GetUserResponse struct {
+	BaseResponse
+	Data User `json:"data"`
+}
+
+type LoginData struct {
+	Token string `json:"token"`
+	User  User   `json:"user"`
+}
+
+type LoginRequest struct {
+	Username string `json:"username" validate:"required"`
+	Password string `json:"password" validate:"required"`
+}
+
+type LoginResponse struct {
+	BaseResponse
+	Data LoginData `json:"data"`
+}
+
+type PageRequest struct {
+	Page     int `form:"page,default=1"`
+	PageSize int `form:"page_size,default=10"`
+}
+
+type PageResponse struct {
+	Total int64 `json:"total"`
+	Page  int   `json:"page"`
+	Size  int   `json:"size"`
+}
+
+type Photo struct {
+	Id            int64  `json:"id"`
+	Title         string `json:"title"`
+	Description   string `json:"description"`
+	FilePath      string `json:"file_path"`
+	ThumbnailPath string `json:"thumbnail_path"`
+	UserId        int64  `json:"user_id"`
+	CategoryId    int64  `json:"category_id"`
+	CreatedAt     int64  `json:"created_at"`
+	UpdatedAt     int64  `json:"updated_at"`
+}
+
+type PhotoListData struct {
+	PageResponse
+	Photos []Photo `json:"photos"`
+}
+
+type RegisterRequest struct {
+	Username string `json:"username" validate:"required"`
+	Email    string `json:"email" validate:"required,email"`
+	Password string `json:"password" validate:"required,min=6"`
+}
+
+type RegisterResponse struct {
+	BaseResponse
+	Data User `json:"data"`
+}
+
+type UpdateCategoryRequest struct {
+	Id          int64  `path:"id"`
+	Name        string `json:"name,optional"`
+	Description string `json:"description,optional"`
+}
+
+type UpdateCategoryResponse struct {
+	BaseResponse
+	Data Category `json:"data"`
+}
+
+type UpdatePhotoRequest struct {
+	Id          int64  `path:"id"`
+	Title       string `json:"title,optional"`
+	Description string `json:"description,optional"`
+	CategoryId  int64  `json:"category_id,optional"`
+}
+
+type UpdatePhotoResponse struct {
+	BaseResponse
+	Data Photo `json:"data"`
+}
+
+type UpdateUserRequest struct {
+	Id       int64  `path:"id"`
+	Username string `json:"username,optional"`
+	Email    string `json:"email,optional"`
+	Avatar   string `json:"avatar,optional"`
+	Status   int    `json:"status,optional"`
+}
+
+type UpdateUserResponse struct {
+	BaseResponse
+	Data User `json:"data"`
+}
+
+type UploadPhotoRequest struct {
+	Title       string `json:"title" validate:"required"`
+	Description string `json:"description,optional"`
+	CategoryId  int64  `json:"category_id" validate:"required"`
+}
+
+type UploadPhotoResponse struct {
+	BaseResponse
+	Data Photo `json:"data"`
+}
+
+type User struct {
+	Id        int64  `json:"id"`
+	Username  string `json:"username"`
+	Email     string `json:"email"`
+	Avatar    string `json:"avatar"`
+	Status    int    `json:"status"`
+	CreatedAt int64  `json:"created_at"`
+	UpdatedAt int64  `json:"updated_at"`
+}
+
+type UserListData struct {
+	PageResponse
+	Users []User `json:"users"`
+}