feat: Service层接口化

新增Service接口定义（internal/service/interfaces.go）:
- UserService: 用户认证、查询、更新等接口
- ProfileService: 档案CRUD、状态管理接口
- TextureService: 材质管理、收藏功能接口
- TokenService: 令牌生命周期管理接口
- VerificationService: 验证码服务接口
- CaptchaService: 滑动验证码接口
- UploadService: 上传服务接口
- YggdrasilService: Yggdrasil API接口

新增Service实现:
- user_service_impl.go: 用户服务实现
- profile_service_impl.go: 档案服务实现
- texture_service_impl.go: 材质服务实现
- token_service_impl.go: 令牌服务实现

更新Container:
- 添加Service层字段
- 初始化Service实例
- 添加With*Service选项函数

遵循Go最佳实践:
- 接口定义与实现分离
- 依赖通过构造函数注入
- 便于单元测试mock

internal/service/interfaces.go

@@ -0,0 +1,144 @@
+// Package service 定义业务逻辑层接口
+package service
+
+import (
+	"carrotskin/internal/model"
+	"carrotskin/pkg/storage"
+	"context"
+
+	"go.uber.org/zap"
+)
+
+// UserService 用户服务接口
+type UserService interface {
+	// 用户认证
+	Register(username, password, email, avatar string) (*model.User, string, error)
+	Login(usernameOrEmail, password, ipAddress, userAgent string) (*model.User, string, error)
+	
+	// 用户查询
+	GetByID(id int64) (*model.User, error)
+	GetByEmail(email string) (*model.User, error)
+	
+	// 用户更新
+	UpdateInfo(user *model.User) error
+	UpdateAvatar(userID int64, avatarURL string) error
+	ChangePassword(userID int64, oldPassword, newPassword string) error
+	ResetPassword(email, newPassword string) error
+	ChangeEmail(userID int64, newEmail string) error
+	
+	// URL验证
+	ValidateAvatarURL(avatarURL string) error
+	
+	// 配置获取
+	GetMaxProfilesPerUser() int
+	GetMaxTexturesPerUser() int
+}
+
+// ProfileService 档案服务接口
+type ProfileService interface {
+	// 档案CRUD
+	Create(userID int64, name string) (*model.Profile, error)
+	GetByUUID(uuid string) (*model.Profile, error)
+	GetByUserID(userID int64) ([]*model.Profile, error)
+	Update(uuid string, userID int64, name *string, skinID, capeID *int64) (*model.Profile, error)
+	Delete(uuid string, userID int64) error
+	
+	// 档案状态
+	SetActive(uuid string, userID int64) error
+	CheckLimit(userID int64, maxProfiles int) error
+	
+	// 批量查询
+	GetByNames(names []string) ([]*model.Profile, error)
+	GetByProfileName(name string) (*model.Profile, error)
+}
+
+// TextureService 材质服务接口
+type TextureService interface {
+	// 材质CRUD
+	Create(uploaderID int64, name, description, textureType, url, hash string, size int, isPublic, isSlim bool) (*model.Texture, error)
+	GetByID(id int64) (*model.Texture, error)
+	GetByUserID(uploaderID int64, page, pageSize int) ([]*model.Texture, int64, error)
+	Search(keyword string, textureType model.TextureType, publicOnly bool, page, pageSize int) ([]*model.Texture, int64, error)
+	Update(textureID, uploaderID int64, name, description string, isPublic *bool) (*model.Texture, error)
+	Delete(textureID, uploaderID int64) error
+	
+	// 收藏
+	ToggleFavorite(userID, textureID int64) (bool, error)
+	GetUserFavorites(userID int64, page, pageSize int) ([]*model.Texture, int64, error)
+	
+	// 限制检查
+	CheckUploadLimit(uploaderID int64, maxTextures int) error
+}
+
+// TokenService 令牌服务接口
+type TokenService interface {
+	// 令牌管理
+	Create(userID int64, uuid, clientToken string) (*model.Profile, []*model.Profile, string, string, error)
+	Validate(accessToken, clientToken string) bool
+	Refresh(accessToken, clientToken, selectedProfileID string) (string, string, error)
+	Invalidate(accessToken string)
+	InvalidateUserTokens(userID int64)
+	
+	// 令牌查询
+	GetUUIDByAccessToken(accessToken string) (string, error)
+	GetUserIDByAccessToken(accessToken string) (int64, error)
+}
+
+// VerificationService 验证码服务接口
+type VerificationService interface {
+	SendCode(ctx context.Context, email, codeType string) error
+	VerifyCode(ctx context.Context, email, code, codeType string) error
+}
+
+// CaptchaService 滑动验证码服务接口
+type CaptchaService interface {
+	Generate(ctx context.Context) (masterImg, tileImg, captchaID string, y int, err error)
+	Verify(ctx context.Context, dx int, captchaID string) (bool, error)
+}
+
+// UploadService 上传服务接口
+type UploadService interface {
+	GenerateAvatarUploadURL(ctx context.Context, userID int64, fileName string) (*storage.PresignedPostPolicyResult, error)
+	GenerateTextureUploadURL(ctx context.Context, userID int64, fileName, textureType string) (*storage.PresignedPostPolicyResult, error)
+}
+
+// YggdrasilService Yggdrasil服务接口
+type YggdrasilService interface {
+	// 用户认证
+	GetUserIDByEmail(email string) (int64, error)
+	VerifyPassword(password string, userID int64) error
+	
+	// 会话管理
+	JoinServer(serverID, accessToken, selectedProfile, ip string) error
+	HasJoinedServer(serverID, username, ip string) error
+	
+	// 密码管理
+	ResetYggdrasilPassword(userID int64) (string, error)
+	
+	// 序列化
+	SerializeProfile(profile model.Profile) map[string]interface{}
+	SerializeUser(user *model.User, uuid string) map[string]interface{}
+	
+	// 证书
+	GeneratePlayerCertificate(uuid string) (map[string]interface{}, error)
+	GetPublicKey() (string, error)
+}
+
+// Services 服务集合
+type Services struct {
+	User         UserService
+	Profile      ProfileService
+	Texture      TextureService
+	Token        TokenService
+	Verification VerificationService
+	Captcha      CaptchaService
+	Upload       UploadService
+	Yggdrasil    YggdrasilService
+}
+
+// ServiceDeps 服务依赖
+type ServiceDeps struct {
+	Logger  *zap.Logger
+	Storage *storage.StorageClient
+}
+