feat(listing): 编辑已发布账号需先下架, 编号保持不变

Update 增加前置校验, 仅 draft/offline 状态可编辑, published 必须
先主动下架; 编辑后由 initialPublishState 推进到待审核, 审核通过
才重新展示. ListingNo 仅在 Create 时生成, 全程同行更新不变

backend/internal/modules/listing/handler_error.go

@@ -58,6 +58,8 @@ func writeListingError(c *gin.Context, err error) {
 		response.BadRequest(c, "发布信息不符合规则")
 	case errors.Is(err, ErrListingLocked):
 		response.Error(c, http.StatusConflict, "listing_locked", "当前发布不可修改")
+	case errors.Is(err, ErrListingMustOfflineToEdit):
+		response.BadRequest(c, "请先下架后再编辑")
 	case errors.Is(err, ErrPublishCooldown):
 		response.Error(c, http.StatusTooManyRequests, "publish_cooldown", publishCooldownMessage(err))
 	case IsNotFound(err):

backend/internal/modules/listing/mutation.go

@@ -211,6 +211,10 @@ func (r *Repository) Update(ctx context.Context, ownerID uint64, listingID uint6
 		if listingLockedForOwnerMutation(listing) {
 			return ErrListingLocked
 		}
+		// 仅允许草稿/已下架状态编辑；已上架的必须先主动下架，避免在线编辑影响正在出租的账号
+		if listing.Status != "draft" && listing.Status != "offline" {
+			return ErrListingMustOfflineToEdit
+		}
 
 		account.Title = req.Title
 		account.Description = req.Description

backend/internal/modules/listing/service.go

@@ -11,6 +11,7 @@ var (
 	ErrDependencyUnavailable    = errors.New("dependency unavailable")
 	ErrInvalidInput             = errors.New("invalid listing input")
 	ErrListingLocked            = errors.New("listing locked")
+	ErrListingMustOfflineToEdit = errors.New("listing must be offline to edit")
 	ErrPublishCooldown          = errors.New("listing publish cooldown")
 	ErrMissingTitle             = errors.New("missing listing title")
 	ErrMissingServerRegion      = errors.New("missing server region")