fix(protocol): save DJ pay details without blocking on due-sum mismatch

Persist payment before samples to avoid consuming sample codes on validation failure, soft-delete samples on create rollback, and surface DJ due-amount mismatch as a hint only.

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

web-admin/src/utils/protocol-pay-mode-switch.ts

@@ -54,6 +54,20 @@ export function calcRemainingAmount(contractAmount: number | null, details: Deta
   return Math.round(remaining * 100) / 100
 }
 
+/** 趸交：应缴合计与合同金额不一致时返回提醒文案（不阻断保存） */
+export function djDueAmountMismatchHint(
+  contractAmount: number | null | undefined,
+  details: DetailLike[]
+): string | null {
+  if (contractAmount == null || Number(contractAmount) === 0) return null
+  const totalDue = details.reduce((sum, d) => sum + (Number(d.dueAmount) || 0), 0)
+  const contract = Number(contractAmount)
+  if (Math.abs(totalDue - contract) > 0.015) {
+    return `趸交各明细应缴金额之和应为 ${contract.toFixed(2)}，当前为 ${totalDue.toFixed(2)}，请核对`
+  }
+  return null
+}
+
 function formatMoneySummary(v: number): string {
   return `¥${v.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ',')}`
 }