feat(distribution): 补齐退款加价回退、本站自卖与开通默认规则

退款时压缩卖方加价，人工/自动批次仅完结单可入账，号主收入进主站钱包；仲裁后重算释放并支持作废未入账 DS。开通时四种模式按默认生效，对外口径合并为 35/40/25，不再单独展示通道费。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/internal/modules/distribution/release_test.go

@@ -441,3 +441,37 @@ func TestThreePartyRefundAfterReleaseReversesReceiverWallet(t *testing.T) {
 		t.Fatalf("seller wallet B = %d, want 400", walletB.AvailableBalanceCent)
 	}
 }
+
+func TestAutoReleaseDueSettlementsIncludesClosedOrders(t *testing.T) {
+	db := distributionTestDB(t)
+	repo := NewRepository(db)
+	now := time.Now()
+	site := mustCreateDistSite(t, db, "closed_site", "关单释放站", "closed.dist.com")
+	rule := mustCreateActiveRule(t, db, site.ID, ModeTwoPartyDistributorReceive, now)
+	past := now.Add(-time.Minute)
+	order := model.RentalOrder{
+		OrderNo: "ORD-CLOSED-1", ListingID: 1, AccountID: 2, OwnerID: 3, RenterID: 4,
+		Status: "closed", RentAmountCent: 10000, OwnerRentAmountCent: 6000, RefundStatus: "none",
+		DistributionSiteID: &site.ID, DistributionRuleVersionID: &rule.ID,
+	}
+	if err := db.Create(&order).Error; err != nil {
+		t.Fatal(err)
+	}
+	if err := db.Create(&model.DistributionOrderFinancial{
+		OrderID: order.ID, SiteID: site.ID, RuleVersionID: rule.ID,
+		GrossPaidAmountCent: 10000, NetPaidAmountCent: 0, SplitBaseAmountCent: 0,
+		SettlementStatus: "pending", ReleaseAt: &past,
+	}).Error; err != nil {
+		t.Fatal(err)
+	}
+	if err := db.Create(&model.DistributionOrderParty{
+		OrderID: order.ID, SiteID: site.ID, PartyRole: "distributor_receive",
+		PartyType: PartyTypeSite, PartyID: site.ID, IncomeAmountCent: 700,
+	}).Error; err != nil {
+		t.Fatal(err)
+	}
+	released, err := repo.AutoReleaseDueSettlements(t.Context())
+	if err != nil || released != 1 {
+		t.Fatalf("closed order release = %d err=%v, want 1", released, err)
+	}
+}