feat(#4): 删除抽奖活动接口 DELETE /admin/lottery/activities/:id

- 软删活动 + 硬删其奖品（同事务）+ 审计日志
- 运行中的活动禁止删除（需先暂停）

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apis/admin/lottery.api

@@ -43,6 +43,10 @@ service ppanel {
 	@handler UpdateLotteryRules
 	put /activities/rules (UpdateAdminLotteryRulesRequest)
 
+	@doc "Delete activity (soft-delete; running must be paused first)"
+	@handler DeleteLotteryActivity
+	delete /activities/:id (AdminActivityIdRequest)
+
 	@doc "Create prize"
 	@handler CreateLotteryPrize
 	post /prizes (CreateAdminLotteryPrizeRequest) returns (AdminLotteryPrize)

internal/handler/admin/lottery/lottery_handler.go

@@ -175,3 +175,20 @@ func GrantLotteryChanceHandler(svcCtx *svc.ServiceContext) func(c *gin.Context)
 		result.HttpResult(c, nil, l.GrantLotteryChance(&req))
 	}
 }
+
+// DeleteLotteryActivityHandler DELETE /v1/admin/lottery/activities/:id
+func DeleteLotteryActivityHandler(svcCtx *svc.ServiceContext) func(c *gin.Context) {
+	return func(c *gin.Context) {
+		var req types.AdminActivityIdRequest
+		_ = c.ShouldBind(&req)
+		if id, err := strconv.ParseInt(c.Param("id"), 10, 64); err == nil {
+			req.Id = id
+		}
+		if err := svcCtx.Validate(&req); err != nil {
+			result.ParamErrorResult(c, err)
+			return
+		}
+		l := adminlottery.NewDeleteLotteryActivityLogic(c.Request.Context(), svcCtx)
+		result.HttpResult(c, nil, l.DeleteLotteryActivity(&req))
+	}
+}

internal/handler/lottery_routes.go

@@ -33,6 +33,7 @@ func registerLotteryRoutes(router *gin.Engine, serverCtx *svc.ServiceContext) {
 		adminGroup.POST("/activities/publish", adminLottery.PublishLotteryActivityHandler(serverCtx))
 		adminGroup.POST("/activities/pause", adminLottery.PauseLotteryActivityHandler(serverCtx))
 		adminGroup.PUT("/activities/rules", adminLottery.UpdateLotteryRulesHandler(serverCtx))
+		adminGroup.DELETE("/activities/:id", adminLottery.DeleteLotteryActivityHandler(serverCtx))
 
 		adminGroup.POST("/prizes", adminLottery.CreateLotteryPrizeHandler(serverCtx))
 		adminGroup.PUT("/prizes/:id", adminLottery.UpdateLotteryPrizeHandler(serverCtx))

internal/logic/admin/lottery/lottery.go

@@ -318,6 +318,55 @@ func (l *PauseLotteryActivityLogic) PauseLotteryActivity(req *types.AdminActivit
 	return t.run(req.Id)
 }
 
+// ---- DeleteLotteryActivity -------------------------------------------------
+
+type DeleteLotteryActivityLogic struct {
+	logger.Logger
+	ctx    context.Context
+	svcCtx *svc.ServiceContext
+}
+
+func NewDeleteLotteryActivityLogic(ctx context.Context, svcCtx *svc.ServiceContext) *DeleteLotteryActivityLogic {
+	return &DeleteLotteryActivityLogic{Logger: logger.WithContext(ctx), ctx: ctx, svcCtx: svcCtx}
+}
+
+// DeleteLotteryActivity 软删活动 + 硬删其奖品（同事务）。运行中的活动禁止删除，
+// 需先暂停，避免误删正在进行的抽奖。历史抽奖记录/快照保留（独立于奖品行）。
+func (l *DeleteLotteryActivityLogic) DeleteLotteryActivity(req *types.AdminActivityIdRequest) error {
+	actor := currentAdminId(l.ctx)
+	if actor == 0 {
+		return xerr.NewErrCode(xerr.ErrorTokenInvalid)
+	}
+	return l.svcCtx.DB.WithContext(l.ctx).Transaction(func(tx *gorm.DB) error {
+		var a modelLottery.Activity
+		if err := tx.Where("id = ?", req.Id).First(&a).Error; err != nil {
+			if errors.Is(err, gorm.ErrRecordNotFound) {
+				return xerr.NewErrCode(xerr.LotteryActivityEnded)
+			}
+			return errors.Wrap(xerr.NewErrCode(xerr.DatabaseQueryError), err.Error())
+		}
+		if a.Status == modelLottery.ActivityStatusRunning {
+			return xerr.NewErrCodeMsg(xerr.InvalidParams, "运行中的活动请先暂停再删除")
+		}
+		// 软删活动（Activity 有 gorm.DeletedAt）。
+		if err := tx.Delete(&modelLottery.Activity{}, req.Id).Error; err != nil {
+			return errors.Wrap(xerr.NewErrCode(xerr.DatabaseDeletedError), err.Error())
+		}
+		// 硬删奖品（Prize 无软删字段），避免残留孤儿奖品。
+		if err := tx.Where("activity_id = ?", req.Id).Delete(&modelLottery.Prize{}).Error; err != nil {
+			return errors.Wrap(xerr.NewErrCode(xerr.DatabaseDeletedError), err.Error())
+		}
+		ip, ua := requestMeta(l.ctx)
+		return audit.WriteAdminAction(l.ctx, tx, audit.Entry{
+			ActorUserId: actor,
+			Action:      audit.ActionLotteryActivityDelete,
+			TargetIds:   int64ToStr(req.Id),
+			IP:          ip,
+			UserAgent:   ua,
+		})
+	})
+}
+
 // ---- UpdateLotteryRules (with caps) ----------------------------------------
 
 type UpdateLotteryRulesLogic struct {