refactor(finance)!: 强制渠道模型，移除旧履约方式与同步链路

- 删除 fulfillment_mode 相关的旧同步/回填链路与定时任务
- 删除 cost_finance_sync、成本快照同步、人工商品归一等遗留服务
- 迁移 113 直接删除 order_items.fulfillment_mode 及其索引约束
- 断代脚本自带归档步骤，不再依赖独立回填脚本
- 退款/事实/总账统一走渠道版销售事实

apps/backend/scripts/finance-cutover-v2.ts

@@ -16,9 +16,10 @@ import { closeDb, query } from '../src/db/client.js'
  *         sku_channel_rules（配置）
  *
  * 前置：
- *   1. 迁移 112 已执行；
- *   2. `npm run fulfillment:backfill-channel` 已完成（不允许有 assigned 但无渠道的行）；
- *   3. 已做数据库备份。
+ *   1. 迁移 112/113 已执行；
+ *   2. 已做数据库备份。
+ *
+ * 断代本身包含两步：先把断代前的订单项批量置为 archived，再清理派生数据。
  *
  * 默认 dry-run，只打印将删除的行数；加 `--execute --confirm=2026-10-31` 才真正执行。
  * 不可重复执行：成功后会写入 finance_cutovers，第二次会被拦下。
@@ -77,6 +78,8 @@ async function main() {
 
   await assertNotExecuted()
 
+  const archived = await archiveHistoricalItems()
+
   const deleted: Record<string, number> = {}
   for (const item of [...DERIVED_TABLES].sort((a, b) => a.order - b.order)) {
     const result = await query(
@@ -110,7 +113,13 @@ async function main() {
 
   console.log(
     JSON.stringify(
-      { mode: 'execute', cutoverDate: CUTOVER_DATE, deleted, durationMs: Date.now() - startedAt },
+      {
+        mode: 'execute',
+        cutoverDate: CUTOVER_DATE,
+        archivedItems: archived.updated,
+        deleted,
+        durationMs: Date.now() - startedAt,
+      },
       null,
       2,
     ),
@@ -181,21 +190,48 @@ async function assertPreconditions() {
       `有 ${bad} 行 status=assigned 但 channel 为空；请先执行 fulfillment:backfill-channel`,
     )
   }
+}
 
-  const pendingBackfill = await query<{ count: number }>(
-    `
-      SELECT COUNT(*)::int AS count
-      FROM order_items oi
-      JOIN orders o ON o.id = oi.order_id
-      WHERE (COALESCE(o.paid_at, o.created_at) AT TIME ZONE 'Asia/Shanghai')::date < $1::date
-        AND oi.fulfillment_status <> 'archived'
-    `,
-    [CUTOVER_DATE],
-  )
-  const notArchived = pendingBackfill.rows[0]?.count || 0
-  if (notArchived > 0) {
-    throw new Error(`有 ${notArchived} 行断代前订单项未归档；请先执行 fulfillment:backfill-channel`)
+/**
+ * 断代前的订单项统一置为 archived（分批，避免 42 万行整表更新撞超时）。
+ */
+async function archiveHistoricalItems(): Promise<{ updated: number }> {
+  let cursor = 0
+  let updated = 0
+  for (let batch = 0; batch < 500; batch += 1) {
+    const rows = await query<{ id: string }>(
+      `
+        SELECT oi.id::text
+        FROM order_items oi
+        JOIN orders o ON o.id = oi.order_id
+        WHERE (COALESCE(o.paid_at, o.created_at) AT TIME ZONE 'Asia/Shanghai')::date < $1::date
+          AND oi.fulfillment_status <> 'archived'
+          AND oi.id > $2
+        ORDER BY oi.id
+        LIMIT 20000
+      `,
+      [CUTOVER_DATE, cursor],
+    )
+    if (rows.rows.length === 0) break
+    cursor = Number(rows.rows[rows.rows.length - 1]!.id)
+
+    const result = await query(
+      `
+        UPDATE order_items
+        SET fulfillment_status = 'archived',
+            fulfillment_channel = NULL,
+            fulfillment_source = 'cutover_archive',
+            fulfillment_decided_at = NOW(),
+            updated_at = NOW()
+        WHERE id = ANY($1::bigint[])
+          AND fulfillment_status <> 'archived'
+      `,
+      [rows.rows.map((row) => Number(row.id))],
+    )
+    updated += result.rowCount || 0
+    process.stderr.write(`归档 ${result.rowCount || 0} 行（游标 ${cursor}）\n`)
   }
+  return { updated }
 }
 
 async function assertNotExecuted() {