refactor: Refactor UserFavorites model to UserFavorite for clarity and consistency

- Rename `UserFavorites` struct to `UserFavorite`
- Update the `TableName` method to reflect the new struct name

pkg/models/userFavorite.go

@@ -1,16 +1,13 @@
 package models
 
-import "time"
-
-type UserFavorites struct {
+type UserFavorite struct {
 	BaseModel[UserFavoriteID]
 	UserID       string       `json:"user_id"`
 	PostID       string       `json:"post_id"`
 	UserSourceID UserSourceID `json:"user_source_id"`
 	UserSource   UserSource   `json:"-" gorm:"foreignKey:ID;references:UserSourceID"`
-	CreatedAt    time.Time    `json:"created_at"`
 }
 
-func (UserFavorites) TableName() string {
+func (UserFavorite) TableName() string {
 	return "UserFavorites"
 }