feat: 引入依赖注入模式

- 创建Repository接口定义（UserRepository、ProfileRepository、TextureRepository等）
- 创建Repository接口实现
- 创建依赖注入容器（container.Container）
- 改造Handler层使用依赖注入（AuthHandler、UserHandler、TextureHandler）
- 创建新的路由注册方式（RegisterRoutesWithDI）
- 提供main.go示例文件展示如何使用依赖注入

同时包含之前的安全修复：
- CORS配置安全加固
- 头像URL验证安全修复
- JWT algorithm confusion漏洞修复
- Recovery中间件增强
- 敏感错误信息泄露修复
- 类型断言安全修复

internal/repository/texture_repository_impl.go

@@ -0,0 +1,175 @@
+package repository
+
+import (
+	"carrotskin/internal/model"
+
+	"gorm.io/gorm"
+)
+
+// textureRepositoryImpl TextureRepository的实现
+type textureRepositoryImpl struct {
+	db *gorm.DB
+}
+
+// NewTextureRepository 创建TextureRepository实例
+func NewTextureRepository(db *gorm.DB) TextureRepository {
+	return &textureRepositoryImpl{db: db}
+}
+
+func (r *textureRepositoryImpl) Create(texture *model.Texture) error {
+	return r.db.Create(texture).Error
+}
+
+func (r *textureRepositoryImpl) FindByID(id int64) (*model.Texture, error) {
+	var texture model.Texture
+	err := r.db.Preload("Uploader").First(&texture, id).Error
+	return handleNotFoundResult(&texture, err)
+}
+
+func (r *textureRepositoryImpl) FindByHash(hash string) (*model.Texture, error) {
+	var texture model.Texture
+	err := r.db.Where("hash = ?", hash).First(&texture).Error
+	return handleNotFoundResult(&texture, err)
+}
+
+func (r *textureRepositoryImpl) FindByUploaderID(uploaderID int64, page, pageSize int) ([]*model.Texture, int64, error) {
+	var textures []*model.Texture
+	var total int64
+
+	query := r.db.Model(&model.Texture{}).Where("uploader_id = ? AND status != -1", uploaderID)
+
+	if err := query.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+
+	err := query.Scopes(Paginate(page, pageSize)).
+		Preload("Uploader").
+		Order("created_at DESC").
+		Find(&textures).Error
+
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return textures, total, nil
+}
+
+func (r *textureRepositoryImpl) Search(keyword string, textureType model.TextureType, publicOnly bool, page, pageSize int) ([]*model.Texture, int64, error) {
+	var textures []*model.Texture
+	var total int64
+
+	query := r.db.Model(&model.Texture{}).Where("status = 1")
+
+	if publicOnly {
+		query = query.Where("is_public = ?", true)
+	}
+	if textureType != "" {
+		query = query.Where("type = ?", textureType)
+	}
+	if keyword != "" {
+		query = query.Where("name LIKE ? OR description LIKE ?", "%"+keyword+"%", "%"+keyword+"%")
+	}
+
+	if err := query.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+
+	err := query.Scopes(Paginate(page, pageSize)).
+		Preload("Uploader").
+		Order("created_at DESC").
+		Find(&textures).Error
+
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return textures, total, nil
+}
+
+func (r *textureRepositoryImpl) Update(texture *model.Texture) error {
+	return r.db.Save(texture).Error
+}
+
+func (r *textureRepositoryImpl) UpdateFields(id int64, fields map[string]interface{}) error {
+	return r.db.Model(&model.Texture{}).Where("id = ?", id).Updates(fields).Error
+}
+
+func (r *textureRepositoryImpl) Delete(id int64) error {
+	return r.db.Model(&model.Texture{}).Where("id = ?", id).Update("status", -1).Error
+}
+
+func (r *textureRepositoryImpl) IncrementDownloadCount(id int64) error {
+	return r.db.Model(&model.Texture{}).Where("id = ?", id).
+		UpdateColumn("download_count", gorm.Expr("download_count + ?", 1)).Error
+}
+
+func (r *textureRepositoryImpl) IncrementFavoriteCount(id int64) error {
+	return r.db.Model(&model.Texture{}).Where("id = ?", id).
+		UpdateColumn("favorite_count", gorm.Expr("favorite_count + ?", 1)).Error
+}
+
+func (r *textureRepositoryImpl) DecrementFavoriteCount(id int64) error {
+	return r.db.Model(&model.Texture{}).Where("id = ?", id).
+		UpdateColumn("favorite_count", gorm.Expr("favorite_count - ?", 1)).Error
+}
+
+func (r *textureRepositoryImpl) CreateDownloadLog(log *model.TextureDownloadLog) error {
+	return r.db.Create(log).Error
+}
+
+func (r *textureRepositoryImpl) IsFavorited(userID, textureID int64) (bool, error) {
+	var count int64
+	err := r.db.Model(&model.UserTextureFavorite{}).
+		Where("user_id = ? AND texture_id = ?", userID, textureID).
+		Count(&count).Error
+	return count > 0, err
+}
+
+func (r *textureRepositoryImpl) AddFavorite(userID, textureID int64) error {
+	favorite := &model.UserTextureFavorite{
+		UserID:    userID,
+		TextureID: textureID,
+	}
+	return r.db.Create(favorite).Error
+}
+
+func (r *textureRepositoryImpl) RemoveFavorite(userID, textureID int64) error {
+	return r.db.Where("user_id = ? AND texture_id = ?", userID, textureID).
+		Delete(&model.UserTextureFavorite{}).Error
+}
+
+func (r *textureRepositoryImpl) GetUserFavorites(userID int64, page, pageSize int) ([]*model.Texture, int64, error) {
+	var textures []*model.Texture
+	var total int64
+
+	subQuery := r.db.Model(&model.UserTextureFavorite{}).
+		Select("texture_id").
+		Where("user_id = ?", userID)
+
+	query := r.db.Model(&model.Texture{}).
+		Where("id IN (?) AND status = 1", subQuery)
+
+	if err := query.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+
+	err := query.Scopes(Paginate(page, pageSize)).
+		Preload("Uploader").
+		Order("created_at DESC").
+		Find(&textures).Error
+
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return textures, total, nil
+}
+
+func (r *textureRepositoryImpl) CountByUploaderID(uploaderID int64) (int64, error) {
+	var count int64
+	err := r.db.Model(&model.Texture{}).
+		Where("uploader_id = ? AND status != -1", uploaderID).
+		Count(&count).Error
+	return count, err
+}
+