fix: 拆分 RabbitMQ Channel，修复新视频不出现在推荐列表的问题

- RabbitMQ 结构体移除共享 Ch 字段，仅管理 Connection
- 每个MQ组件(Like/Comment/Social/Popularity/Timeline)持有独立 Channel
- Timeline Consumer 使用独立 Channel 并加入自动重连机制
- Redis 操作超时从 50ms 调整为 500ms，避免 NACK 循环
- router.go 中 notification 相关逻辑适配新 API

backend/internal/worker/outboxworker.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"feedsystem_video_go/internal/middleware/rabbitmq"
-	"feedsystem_video_go/internal/middleware/redis"
+	rediscache "feedsystem_video_go/internal/middleware/redis"
 	"feedsystem_video_go/internal/video"
 	"fmt"
 	"log"
@@ -15,7 +15,7 @@ import (
 )
 
 func StartOutboxPoller(db *gorm.DB, tmq *rabbitmq.TimelineMQ) {
-	if db == nil || tmq == nil || tmq.RabbitMQ == nil || tmq.Ch == nil {
+	if db == nil || tmq == nil {
 		log.Printf("Outbox poller disabled: timeline mq is not initialized")
 		return
 	}
@@ -46,9 +46,9 @@ func StartOutboxPoller(db *gorm.DB, tmq *rabbitmq.TimelineMQ) {
 	}()
 }
 
-func StartConsumer(tmq *rabbitmq.TimelineMQ, queueName string, redisClient *redis.Client) {
-	if tmq == nil || tmq.RabbitMQ == nil || tmq.Ch == nil {
-		log.Printf("Timeline consumer disabled: timeline mq is not initialized")
+func StartConsumer(tmq *rabbitmq.TimelineMQ, queueName string, redisClient *rediscache.Client, rmq *rabbitmq.RabbitMQ) {
+	if tmq == nil || rmq == nil || rmq.Conn == nil {
+		log.Printf("Timeline consumer disabled: rabbitmq is not initialized")
 		return
 	}
 	if redisClient == nil {
@@ -56,54 +56,64 @@ func StartConsumer(tmq *rabbitmq.TimelineMQ, queueName string, redisClient *redi
 		return
 	}
 
-	msgs, err := tmq.Ch.Consume(
-		queueName,
-		"",
-		false,
-		false,
-		false,
-		false,
-		nil,
-	)
-
-	if err != nil {
-		log.Printf("注册消费失败")
-		return
-	}
-
 	go func() {
-		for msg := range msgs {
-			var event rabbitmq.TimelineEvent
-			err := json.Unmarshal(msg.Body, &event)
-
+		for {
+			// 每次重连创建独立的 Channel，不与发布者共用
+			ch, err := rmq.NewChannel()
 			if err != nil {
-				log.Printf("反序列化失败")
+				log.Printf("Timeline consumer: 创建 Channel 失败: %v, 5秒后重试", err)
+				time.Sleep(5 * time.Second)
+				continue
+			}
+
+			if err := ch.Qos(10, 0, false); err != nil {
+				log.Printf("Timeline consumer: QoS 设置失败: %v", err)
+			}
+
+			msgs, err := ch.Consume(queueName, "", false, false, false, false, nil)
+			if err != nil {
+				log.Printf("Timeline consumer: 注册消费失败: %v, 5秒后重试", err)
+				ch.Close()
+				time.Sleep(5 * time.Second)
+				continue
+			}
+
+			log.Printf("Timeline consumer 已启动, queue=%s", queueName)
+
+			for msg := range msgs {
+				var event rabbitmq.TimelineEvent
+				if err := json.Unmarshal(msg.Body, &event); err != nil {
+					log.Printf("Timeline consumer: 反序列化失败: %v", err)
+					msg.Ack(false)
+					continue
+				}
+
+				ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
+				timelineKey := redisClient.Key("feed:global_timeline")
+				err = redisClient.ZAdd(ctx, timelineKey, oredis.Z{
+					Score:  float64(event.CreateTime),
+					Member: fmt.Sprintf("%d", event.VideoID),
+				})
+
+				if err != nil {
+					log.Printf("Timeline consumer: 写入Zset失败: %v", err)
+					msg.Nack(false, true)
+					cancel()
+					continue
+				}
+
+				if err := redisClient.ZRemRangeByRank(ctx, timelineKey, 0, -1001); err != nil {
+					log.Printf("Timeline consumer: ZRem失败: %v", err)
+				}
+
 				msg.Ack(false)
-				continue
-			}
-
-			ctx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
-			timelineKey := redisClient.Key("feed:global_timeline")
-			err = redisClient.ZAdd(ctx, timelineKey, oredis.Z{
-				Score:  float64(event.CreateTime),
-				Member: fmt.Sprintf("%d", event.VideoID),
-			})
-
-			if err != nil {
-				log.Printf("写入Zset失败")
-				msg.Nack(false, true)
 				cancel()
-				continue
 			}
 
-			err = redisClient.ZRemRangeByRank(ctx, timelineKey, 0, -1001)
-
-			if err != nil {
-				log.Printf("ZRem失败")
-			}
-
-			msg.Ack(false)
-			cancel()
+			// msgs channel 关闭说明 AMQP Channel 断开，关闭并重连
+			ch.Close()
+			log.Printf("Timeline consumer: Channel 断开, 5秒后重连...")
+			time.Sleep(5 * time.Second)
 		}
 	}()
 }