归档一次性佣金配置落库与累计触发修复，同步规范文档到主 specs

- 归档 fix-one-time-commission-config-and-accumulation 到 archive/2026-01-29-*
- 同步 delta specs 到主规范（one-time-commission-trigger、commission-calculation）
- 新增累计触发逻辑文档和测试用例
- 修复一次性佣金配置落库和累计充值更新逻辑

tests/unit/commission_withdrawal_setting_service_test.go

@@ -159,6 +159,9 @@ func TestCommissionWithdrawalSettingService_GetCurrent(t *testing.T) {
 	rdb := testutils.GetTestRedis(t)
 	testutils.CleanTestRedisKeys(t, rdb)
 
+	// 清理已有的活跃配置，确保测试隔离
+	tx.Exec("UPDATE tb_commission_withdrawal_setting SET is_active = false WHERE is_active = true")
+
 	accountStore := postgres.NewAccountStore(tx, rdb)
 	settingStore := postgres.NewCommissionWithdrawalSettingStore(tx, rdb)