优化号主交接超时卡死问题

- 号主交接超时(owner_timeout)后允许补提交交接说明，避免临时延误导致订单卡死
- 后台新增"重置交接"动作，可将超时订单恢复为待号主交接并刷新计时
- 交接超时改以进入待交接时刻为基准计算，新增 handoff_started_at 字段

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

backend/internal/modules/order/service.go

@@ -6,23 +6,24 @@ import (
 )
 
 var (
-	ErrDependencyUnavailable  = errors.New("dependency unavailable")
-	ErrInvalidRentHours       = errors.New("invalid rent hours")
-	ErrListingUnavailable     = errors.New("listing unavailable")
-	ErrCannotRentOwnListing   = errors.New("cannot rent own listing")
-	ErrInsufficientBalance    = errors.New("insufficient balance")
-	ErrOrderCannotPay         = errors.New("order cannot pay")
-	ErrChannelPaymentRequired = errors.New("channel payment required")
-	ErrOrderCannotCancel      = errors.New("order cannot cancel")
-	ErrOrderCannotHandoff     = errors.New("order cannot handoff")
-	ErrOrderCannotReceive     = errors.New("order cannot receive")
-	ErrOrderCannotReturn      = errors.New("order cannot return")
-	ErrOrderCannotComplete    = errors.New("order cannot complete")
-	ErrCheckoutCannotSubmit   = errors.New("checkout cannot submit")
-	ErrCheckoutCannotConfirm  = errors.New("checkout cannot confirm")
-	ErrCheckoutCannotCounter  = errors.New("checkout cannot counter")
-	ErrInvalidCheckoutAmount  = errors.New("invalid checkout amount")
-	ErrPermissionDenied       = errors.New("permission denied")
+	ErrDependencyUnavailable   = errors.New("dependency unavailable")
+	ErrInvalidRentHours        = errors.New("invalid rent hours")
+	ErrListingUnavailable      = errors.New("listing unavailable")
+	ErrCannotRentOwnListing    = errors.New("cannot rent own listing")
+	ErrInsufficientBalance     = errors.New("insufficient balance")
+	ErrOrderCannotPay          = errors.New("order cannot pay")
+	ErrChannelPaymentRequired  = errors.New("channel payment required")
+	ErrOrderCannotCancel       = errors.New("order cannot cancel")
+	ErrOrderCannotHandoff      = errors.New("order cannot handoff")
+	ErrOrderCannotResetHandoff = errors.New("order cannot reset handoff")
+	ErrOrderCannotReceive      = errors.New("order cannot receive")
+	ErrOrderCannotReturn       = errors.New("order cannot return")
+	ErrOrderCannotComplete     = errors.New("order cannot complete")
+	ErrCheckoutCannotSubmit    = errors.New("checkout cannot submit")
+	ErrCheckoutCannotConfirm   = errors.New("checkout cannot confirm")
+	ErrCheckoutCannotCounter   = errors.New("checkout cannot counter")
+	ErrInvalidCheckoutAmount   = errors.New("invalid checkout amount")
+	ErrPermissionDenied        = errors.New("permission denied")
 )
 
 const internalOrderHours = 24
@@ -185,6 +186,16 @@ func (s *Service) AdminMarkAbnormal(ctx context.Context, adminID uint64, orderID
 	return s.repo.AdminMarkAbnormal(ctx, adminID, orderID, req, meta)
 }
 
+func (s *Service) AdminResetHandoff(ctx context.Context, adminID uint64, orderID uint64, req AdminActionRequest, meta AuditMeta) error {
+	if s.repo == nil {
+		return ErrDependencyUnavailable
+	}
+	if orderID == 0 || req.Reason == "" {
+		return ErrOrderCannotResetHandoff
+	}
+	return s.repo.AdminResetHandoff(ctx, adminID, orderID, req, meta)
+}
+
 func (s *Service) AdminRefund(ctx context.Context, orderID uint64) (*RefundStatusDTO, error) {
 	if s.repo == nil {
 		return nil, ErrDependencyUnavailable