feat:添加热榜功能并添加了增加热度的方法。

backend/internal/feed/entity.go

@@ -1,5 +1,7 @@
 package feed
 
+import "time"
+
 type FeedAuthor struct {
 	ID       uint   `json:"id"`
 	Username string `json:"username"`
@@ -56,3 +58,25 @@ type ListByFollowingResponse struct {
 	NextTime  int64           `json:"next_time"`
 	HasMore   bool            `json:"has_more"`
 }
+
+type ListByPopularityRequest struct {
+	Limit          int   `json:"limit"`
+	AsOf           int64 `json:"as_of"`  // 服务器返回的分钟时间戳；第一页传0
+	Offset         int   `json:"offset"` // 下一页从这里开始；第一页传0
+	LatestIDBefore *uint `json:"latest_id_before,omitempty"`
+
+	// DB fallback 用（可选）
+	LatestPopularity int64     `json:"latest_popularity"`
+	LatestBefore     time.Time `json:"latest_before"`
+}
+
+type ListByPopularityResponse struct {
+	VideoList  []FeedVideoItem `json:"video_list"`
+	AsOf       int64           `json:"as_of"`
+	NextOffset int             `json:"next_offset"`
+	HasMore    bool            `json:"has_more"`
+
+	NextLatestPopularity *int64     `json:"next_latest_popularity,omitempty"`
+	NextLatestBefore     *time.Time `json:"next_latest_before,omitempty"`
+	NextLatestIDBefore   *uint      `json:"next_latest_id_before,omitempty"`
+}