fix(worker-platform): 修复售后欠款抵扣导致验收失败，并支持余额偿还

有待还欠款时结算写入 settled_at 发生 timestamptz/text 类型错误会整单 500；顺带支持充值/解冻自动偿还与后台手动偿还。

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

apps/frontend/src/services/admin/worker-platform.ts

@@ -582,6 +582,20 @@ export function resolveAdminAfterSalesCase(
   }>(`/api/v1/admin/worker-platform/after-sales-cases/${caseId}/resolve`, payload)
 }
 
+export function repayAdminAfterSalesCaseDebt(
+  caseId: number,
+  payload: {
+    amount?: number | null
+    note?: string
+  } = {},
+) {
+  return apiPost<{
+    case: WorkerAfterSalesCase
+    repaidAmount: number
+    availableAfter: number
+  }>(`/api/v1/admin/worker-platform/after-sales-cases/${caseId}/repay`, payload)
+}
+
 export function fetchAdminWorkOrderEvents(workOrderId: number) {
   return apiGet<{ items: WorkOrderEvent[] }>(
     `/api/v1/admin/worker-platform/orders/${workOrderId}/events`,