refactor(server): decouple services and improve architecture

- Introduce interfaces for all major services (JWT, PostAI, Comment, Message, Notification, QRCodeLogin, Upload, Vote, etc.) to support dependency inversion.
- Move query parameters from `internal/dto` to a new `internal/query` package to separate request payloads from data transfer objects.
- Refactor `internal/router` to use embedded `RouterDeps` for cleaner dependency management.
- Decouple handlers from repositories by injecting services instead of direct repository access, ensuring proper layering.
- Improve database initialization by moving it from `internal/model` to `internal/database`.
- Optimize message decryption by implementing a more efficient `BatchDecrypt` method in `MessageEncryptor` using a worker pool.
- Enhance error handling and security by implementing fail-fast checks for encryption key length during startup.
- Clean up unused code, including the `avatar` package and several unused DTOs.

internal/service/notification_service.go

@@ -18,22 +18,34 @@ const (
 	NotificationCacheJitter    = 0.1
 )
 
-// NotificationService 通知服务
-type NotificationService struct {
+// NotificationService 通知服务接口
+type NotificationService interface {
+	Create(ctx context.Context, userID string, notificationType model.NotificationType, title, content string) (*model.Notification, error)
+	GetByUserID(ctx context.Context, userID string, page, pageSize int, unreadOnly bool) ([]*model.Notification, int64, error)
+	MarkAsReadWithUserID(ctx context.Context, id, userID string) error
+	MarkAllAsRead(ctx context.Context, userID string) error
+	GetUnreadCount(ctx context.Context, userID string) (int64, error)
+	DeleteNotification(ctx context.Context, id, userID string) error
+	ClearAllNotifications(ctx context.Context, userID string) error
+	GetNotificationsByCursor(ctx context.Context, userID string, unreadOnly bool, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Notification], error)
+}
+
+// notificationService 通知服务实现
+type notificationService struct {
 	notificationRepo repository.NotificationRepository
 	cache            cache.Cache
 }
 
 // NewNotificationService 创建通知服务
-func NewNotificationService(notificationRepo repository.NotificationRepository, cacheBackend cache.Cache) *NotificationService {
-	return &NotificationService{
+func NewNotificationService(notificationRepo repository.NotificationRepository, cacheBackend cache.Cache) NotificationService {
+	return &notificationService{
 		notificationRepo: notificationRepo,
 		cache:            cacheBackend,
 	}
 }
 
 // Create 创建通知
-func (s *NotificationService) Create(ctx context.Context, userID string, notificationType model.NotificationType, title, content string) (*model.Notification, error) {
+func (s *notificationService) Create(ctx context.Context, userID string, notificationType model.NotificationType, title, content string) (*model.Notification, error) {
 	notification := &model.Notification{
 		UserID:  userID,
 		Type:    notificationType,
@@ -54,12 +66,12 @@ func (s *NotificationService) Create(ctx context.Context, userID string, notific
 }
 
 // GetByUserID 获取用户通知
-func (s *NotificationService) GetByUserID(ctx context.Context, userID string, page, pageSize int, unreadOnly bool) ([]*model.Notification, int64, error) {
+func (s *notificationService) GetByUserID(ctx context.Context, userID string, page, pageSize int, unreadOnly bool) ([]*model.Notification, int64, error) {
 	return s.notificationRepo.GetByUserID(userID, page, pageSize, unreadOnly)
 }
 
 // MarkAsReadWithUserID 标记为已读（带用户ID，验证所有权）
-func (s *NotificationService) MarkAsReadWithUserID(ctx context.Context, id, userID string) error {
+func (s *notificationService) MarkAsReadWithUserID(ctx context.Context, id, userID string) error {
 	notification, err := s.notificationRepo.GetByID(id)
 	if err != nil {
 		return err
@@ -79,7 +91,7 @@ func (s *NotificationService) MarkAsReadWithUserID(ctx context.Context, id, user
 }
 
 // MarkAllAsRead 标记所有为已读
-func (s *NotificationService) MarkAllAsRead(ctx context.Context, userID string) error {
+func (s *notificationService) MarkAllAsRead(ctx context.Context, userID string) error {
 	err := s.notificationRepo.MarkAllAsRead(userID)
 	if err != nil {
 		return err
@@ -92,7 +104,7 @@ func (s *NotificationService) MarkAllAsRead(ctx context.Context, userID string)
 }
 
 // GetUnreadCount 获取未读数量（带缓存）
-func (s *NotificationService) GetUnreadCount(ctx context.Context, userID string) (int64, error) {
+func (s *notificationService) GetUnreadCount(ctx context.Context, userID string) (int64, error) {
 	cacheSettings := cache.GetSettings()
 	unreadTTL := cacheSettings.UnreadCountTTL
 	if unreadTTL <= 0 {
@@ -122,7 +134,7 @@ func (s *NotificationService) GetUnreadCount(ctx context.Context, userID string)
 }
 
 // DeleteNotification 删除通知（带用户验证）
-func (s *NotificationService) DeleteNotification(ctx context.Context, id, userID string) error {
+func (s *notificationService) DeleteNotification(ctx context.Context, id, userID string) error {
 	// 先检查通知是否属于该用户
 	notification, err := s.notificationRepo.GetByID(id)
 	if err != nil {
@@ -144,7 +156,7 @@ func (s *NotificationService) DeleteNotification(ctx context.Context, id, userID
 }
 
 // ClearAllNotifications 清空所有通知
-func (s *NotificationService) ClearAllNotifications(ctx context.Context, userID string) error {
+func (s *notificationService) ClearAllNotifications(ctx context.Context, userID string) error {
 	err := s.notificationRepo.DeleteAllByUserID(userID)
 	if err != nil {
 		return err
@@ -157,7 +169,7 @@ func (s *NotificationService) ClearAllNotifications(ctx context.Context, userID
 }
 
 // GetNotificationsByCursor 游标分页获取用户通知
-func (s *NotificationService) GetNotificationsByCursor(ctx context.Context, userID string, unreadOnly bool, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Notification], error) {
+func (s *notificationService) GetNotificationsByCursor(ctx context.Context, userID string, unreadOnly bool, req *cursor.PageRequest) (*cursor.CursorPageResult[*model.Notification], error) {
 	return s.notificationRepo.GetNotificationsByCursor(ctx, userID, unreadOnly, req)
 }