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/cache/cache.go

@@ -8,6 +8,8 @@ import (
 	"math/rand"
 	"sync"
 	"time"
+
+	"github.com/redis/go-redis/v9"
 )
 
 var ErrKeyNotFound = errors.New("key not found")
@@ -52,6 +54,10 @@ type Cache interface {
 	ZRangeByScore(ctx context.Context, key string, min, max string, offset, count int64) ([]string, error)
 	// ZRevRangeByScore 按分数范围获取成员（降序）
 	ZRevRangeByScore(ctx context.Context, key string, max, min string, offset, count int64) ([]string, error)
+	// ZRevRange 按排名倒序取成员（score 从高到低，start/stop 为排名下标，含端点）
+	ZRevRange(ctx context.Context, key string, start, stop int64) ([]string, error)
+	// ZReplaceSortedSet 原子替换整个 ZSET（先删后批量写入）
+	ZReplaceSortedSet(ctx context.Context, key string, members []redis.Z) error
 	// ZRem 删除 Sorted Set 成员
 	ZRem(ctx context.Context, key string, members ...interface{}) error
 	// ZCard 获取 Sorted Set 成员数量
@@ -130,6 +136,11 @@ func normalizeKey(key string) string {
 	return cmp.Or(settings.KeyPrefix, "") + ":" + key
 }
 
+// ResolveKey 返回带全局前缀的实际 Redis 键（供需直连 Redis 的组件使用）
+func ResolveKey(key string) string {
+	return normalizeKey(key)
+}
+
 func normalizePrefix(prefix string) string {
 	return cmp.Or(settings.KeyPrefix, "") + ":" + prefix
 }