feat(auth): add Casbin RBAC and user activity tracking

Integrate Casbin for role-based access control with admin routes for role management. Add user activity logging service to track login and refresh events. Refactor audit service to use AI-based content moderation.

internal/wire/repository.go

@@ -1,9 +1,11 @@
 package wire
 
 import (
+	"carrot_bbs/internal/cache"
 	"carrot_bbs/internal/repository"
 
 	"github.com/google/wire"
+	"gorm.io/gorm"
 )
 
 // RepositorySet Repository 层 Provider Set
@@ -20,8 +22,14 @@ var RepositorySet = wire.NewSet(
 	repository.NewStickerRepository,
 	repository.NewVoteRepository,
 	repository.NewScheduleRepository,
+	ProvideUserActivityRepository,
 )
 
+// ProvideUserActivityRepository 提供用户活跃数据仓储
+func ProvideUserActivityRepository(db *gorm.DB, cache cache.Cache) *repository.UserActivityRepository {
+	return repository.NewUserActivityRepository(db, cache)
+}
+
 // Note: 以下 Repository 返回接口类型而非指针，需要单独处理
 // - ScheduleRepository (repository.ScheduleRepository)
 // - StickerRepository (repository.StickerRepository)