refactor: 文件行数超标拆解（7个文件→14个文件，全部≤200行）

- 移动本地接口定义到 interfaces.go 和 admin/interfaces.go
- favorite_controller.go → favorite_item_controller.go
- space_controller.go → space_loaders.go
- settings_controller.go → settings_api_audit.go
- admin_energy_controller.go → admin_energy_api_controller.go
- admin_post_controller.go → admin_post_action_controller.go
- comment_repo.go → comment_mention_repo.go
- post_repo.go → post_stats_repo.go

internal/controller/interfaces.go

@@ -1,6 +1,8 @@
 package controller
 
 import (
+	"io"
+
 	"metazone.cc/metalab/internal/middleware"
 	"metazone.cc/metalab/internal/model"
 	"metazone.cc/metalab/internal/service"
@@ -130,3 +132,56 @@ type followUseCase interface {
 	ListFollowers(userID, currentUserID uint, page, pageSize int) (*service.FollowListResult, error)
 	ListFollowing(userID, currentUserID uint, page, pageSize int) (*service.FollowListResult, error)
 }
+
+// favoriteUseCase FavoriteController 对 FavoriteService 的最小依赖（ISP：9 个方法）
+type favoriteUseCase interface {
+	ListFolders(userID uint) (*service.FavoriteListResult, error)
+	CreateFolder(userID uint, name, description string, isPublic bool) (*model.Folder, error)
+	UpdateFolder(userID, folderID uint, name, description string, isPublic bool) error
+	DeleteFolder(userID, folderID uint) error
+	ListFolderItems(userID, folderID uint, page, pageSize int) (*service.FolderItemsResult, error)
+	AddFavorite(userID, postID uint, folderID *uint) error
+	RemoveFavorite(userID, postID uint) error
+	ToggleFavorite(userID, postID uint) (bool, error)
+	GetPostFavoriteStatus(userID, postID uint) (*service.FavoriteStatus, error)
+}
+
+// profileProvider SettingsController 对 AuthService 的最小依赖（ISP：4 个方法）
+type profileProvider interface {
+	GetProfile(userID uint) (*model.User, error)
+	UpdateProfile(userID uint, username, bio string) error
+	ChangePassword(userID uint, currentPassword, newPassword string) error
+	DeleteAccount(userID uint, password, reason string) error
+}
+
+// avatarProvider SettingsController 头像上传对 Service 的最小依赖（ISP：2 个方法）
+type avatarProvider interface {
+	ProcessAvatar(userID uint, file io.Reader, contentType string, cropX, cropY, cropSize int) (string, error)
+	ProcessImage(userID uint, file io.Reader, contentType string, cropX, cropY, cropSize int) (string, error)
+}
+
+// auditSubmittable SettingsController 对 AuditService 的依赖（ISP：4 个方法）
+type auditSubmittable interface {
+	ShouldAudit(userID uint) (bool, error)
+	SubmitProfileChanges(userID uint, currentUser *model.User, newUsername, newBio string) error
+	Submit(userID uint, auditType, newValue string) error
+	GetPendingTypes(userID uint) ([]string, error)
+}
+
+// sessionConfig SettingsController 对配置的最小依赖（ISP：2 个方法）
+type sessionConfig interface {
+	GetIdleTimeout() int
+	GetRememberTimeout() int
+}
+
+// taskCompleter SettingsController 对 LevelService 的依赖（ISP：2 个方法）
+type taskCompleter interface {
+	CompleteTask(userID uint, taskType string) (newExp int, levelUp bool, err error)
+	HasCompletedTask(userID uint, taskType string) (bool, error)
+}
+
+// notifyPrefReader SettingsController 通知偏好的接口（ISP）
+type notifyPrefReader interface {
+	GetNotifyPrefs(userID uint) (map[string]bool, error)
+	UpdateNotifyPref(userID uint, key string, enabled bool) error
+}