fix(chat): 回复后再移出待处理

backend/internal/modules/chat/support.go

@@ -239,6 +239,7 @@ func (r *Repository) listAdminConversations(ctx context.Context, principal Princ
 			COALESCE(explicit_lo.handoff_status, listing_lo.handoff_status) AS latest_handoff_status,
 			COALESCE(explicit_lo.refund_status, listing_lo.refund_status) AS latest_refund_status,
 			lm.sender_type AS last_sender_type, lm.sender_id AS last_sender_id, lm.sender_role AS last_sender_role,
+			CASE WHEN ` + adminNeedsReplyExpression() + ` THEN 1 ELSE 0 END AS needs_reply,
 			(
 				SELECT COUNT(1)
 				FROM chat_messages AS cm
@@ -414,13 +415,7 @@ func adminChatStageCondition(stage string, principal Principal) (string, []inter
 	latestRefundStatus := "COALESCE(explicit_lo.refund_status, listing_lo.refund_status)"
 	switch stage {
 	case adminChatStagePending:
-		return `EXISTS (
-				SELECT 1
-				FROM chat_messages AS cm_pending
-				WHERE cm_pending.conversation_id = c.id
-					  AND (cm_pending.admin_attention_type <> '' OR cm_pending.sender_type = 'user')
-					  AND cm_pending.id > COALESCE(cas.last_read_message_id, 0)
-			)`, nil
+		return adminNeedsReplyExpression(), nil
 	case adminChatStageUnjoined:
 		return latestID + " IS NULL", nil
 	case adminChatStageHandoff:
@@ -438,6 +433,20 @@ func adminChatStageCondition(stage string, principal Principal) (string, []inter
 	}
 }
 
+func adminNeedsReplyExpression() string {
+	return `COALESCE((
+		SELECT MAX(cm_attention.id)
+		FROM chat_messages AS cm_attention
+		WHERE cm_attention.conversation_id = c.id
+		  AND (cm_attention.admin_attention_type <> '' OR cm_attention.sender_type = 'user')
+	), 0) > COALESCE((
+		SELECT MAX(cm_admin.id)
+		FROM chat_messages AS cm_admin
+		WHERE cm_admin.conversation_id = c.id
+		  AND cm_admin.sender_type = 'admin'
+	), 0)`
+}
+
 // ArchiveListingConversation 将商品关联的发布群标记为已归档（解散），并写入系统提示。
 // 用于客服封存订单时同事务解散群聊；发布群不存在时静默跳过，不阻断封存流程。
 // 归档后 SendMessage 的 status 校验会阻断所有成员继续发言。