refactor: remove Gorse integration and implement HotRank feature

- Removed Gorse-related configurations, handlers, and dependencies from the codebase.
- Introduced HotRank feature with configuration options for ranking posts based on recent activity.
- Updated application structure to support HotRank processing, including new caching mechanisms and database interactions.
- Cleaned up related DTOs and repository methods to reflect the removal of Gorse and the addition of HotRank functionality.

internal/model/init.go

@@ -163,6 +163,11 @@ func autoMigrate(db *gorm.DB) error {
 		return err
 	}
 
+	// AutoMigrate 不会删除列：清理已废弃的 posts.hot_score
+	if err := dropPostsHotScoreColumnIfExists(db); err != nil {
+		return fmt.Errorf("drop legacy posts.hot_score: %w", err)
+	}
+
 	// 初始化角色种子数据
 	if err := seedRoles(db); err != nil {
 		return fmt.Errorf("failed to seed roles: %w", err)
@@ -176,6 +181,24 @@ func autoMigrate(db *gorm.DB) error {
 	return nil
 }
 
+// postWithHotScore 仅用于 Migrator 检测/删除旧列（Post 模型已移除 HotScore）
+type postWithHotScore struct {
+	HotScore float64 `gorm:"column:hot_score"`
+}
+
+func (postWithHotScore) TableName() string { return "posts" }
+
+func dropPostsHotScoreColumnIfExists(db *gorm.DB) error {
+	m := db.Migrator()
+	if !m.HasTable(&Post{}) {
+		return nil
+	}
+	if !m.HasColumn(&postWithHotScore{}, "HotScore") {
+		return nil
+	}
+	return m.DropColumn(&postWithHotScore{}, "HotScore")
+}
+
 // seedRoles 初始化角色种子数据
 func seedRoles(db *gorm.DB) error {
 	// 检查是否已有角色数据

internal/model/post.go

@@ -43,7 +43,6 @@ type Post struct {
 	FavoritesCount int     `json:"favorites_count" gorm:"column:favorites_count;default:0"`
 	SharesCount    int     `json:"shares_count" gorm:"column:shares_count;default:0"`
 	ViewsCount     int     `json:"views_count" gorm:"column:views_count;default:0"`
-	HotScore       float64 `json:"hot_score" gorm:"column:hot_score;default:0;index:idx_posts_hot_score_created,priority:1"`
 
 	// 置顶/锁定
 	IsPinned   bool `json:"is_pinned" gorm:"default:false"`
@@ -58,7 +57,7 @@ type Post struct {
 	DeletedAt gorm.DeletedAt `json:"-" gorm:"index"`
 
 	// 时间戳
-	CreatedAt time.Time `json:"created_at" gorm:"autoCreateTime;index:idx_posts_status_created,priority:2,sort:desc;index:idx_posts_user_status_created,priority:3,sort:desc;index:idx_posts_hot_score_created,priority:2,sort:desc"`
+	CreatedAt time.Time `json:"created_at" gorm:"autoCreateTime;index:idx_posts_status_created,priority:2,sort:desc;index:idx_posts_user_status_created,priority:3,sort:desc"`
 	UpdatedAt time.Time `json:"updated_at" gorm:"autoUpdateTime:false"`
 	// ContentEditedAt 仅在实际修改标题/正文/图片时更新，供前端展示「已编辑」；与统计类更新解耦
 	ContentEditedAt *time.Time `json:"content_edited_at,omitempty" gorm:"column:content_edited_at"`