merge upstream main

backend/internal/repository/gateway_cache.go

@@ -39,3 +39,15 @@ func (c *gatewayCache) RefreshSessionTTL(ctx context.Context, groupID int64, ses
 	key := buildSessionKey(groupID, sessionHash)
 	return c.rdb.Expire(ctx, key, ttl).Err()
 }
+
+// DeleteSessionAccountID 删除粘性会话与账号的绑定关系。
+// 当检测到绑定的账号不可用（如状态错误、禁用、不可调度等）时调用，
+// 以便下次请求能够重新选择可用账号。
+//
+// DeleteSessionAccountID removes the sticky session binding for the given session.
+// Called when the bound account becomes unavailable (e.g., error status, disabled,
+// or unschedulable), allowing subsequent requests to select a new available account.
+func (c *gatewayCache) DeleteSessionAccountID(ctx context.Context, groupID int64, sessionHash string) error {
+	key := buildSessionKey(groupID, sessionHash)
+	return c.rdb.Del(ctx, key).Err()
+}