新增: 兑换复验功能

- 新增 exchangeList 接口查询斗鱼真实兑换记录
- 前端添加「兑换复验」标签页
- 点击「🔍 复验」按钮可查询所有账号的兑换记录
- 复验结果与软件内部状态对比，用于验证抢购结果
- 移除 frontend/dist 的 git 跟踪

internal/client/client.go

@@ -406,6 +406,39 @@ func (c *DouyuClient) RoleName(cookie string) (string, error) {
 	return result.Data.GameRole.RoleName, nil
 }
 
+// ExchangeRecord 兑换记录。
+type ExchangeRecord struct {
+	CommodityID   string `json:"commodityId"`
+	CommodityName string `json:"commodityName"`
+	NickName      string `json:"nickName"`
+	ShowName      string `json:"showName"`
+	ExchangeNum   int    `json:"exchangeNum"`
+	Time          string `json:"time"`
+	Score         string `json:"score"`
+}
+
+// ExchangeListResponse 兑换列表响应。
+type ExchangeListResponse struct {
+	Error int    `json:"error"`
+	Msg   string `json:"msg"`
+	Data  struct {
+		List  []ExchangeRecord `json:"list"`
+		Count int              `json:"count"`
+	} `json:"data"`
+}
+
+// ExchangeList 查询兑换记录列表。
+func (c *DouyuClient) ExchangeList(cookie string) ([]ExchangeRecord, error) {
+	var result ExchangeListResponse
+	if err := c.getJSON(constants.ExchangeListURL, cookie, "兑换记录", &result); err != nil {
+		return nil, err
+	}
+	if result.Error != 0 {
+		return nil, fmt.Errorf("兑换记录查询失败: %s", result.Msg)
+	}
+	return result.Data.List, nil
+}
+
 func (c *DouyuClient) getJSON(url, cookie, label string, out any) error {
 	req, err := http.NewRequest("GET", url, nil)
 	if err != nil {