feat(代理自充): AUG26-017 代理自充收款方式与线下预存款审批字段

- 受控配置新增代理在线自充允许范围（仅微信/仅支付宝/同时支持），读侧与创建侧取允许范围与可用商户池交集，两侧失败关闭
- 新增允许范围查询与修改端点，读限代理与平台账号、写限超级管理员，复用受控配置写服务留痕
- tb_agent_recharge_record 新增交易流水号、线下收款方式三列快照与其他凭证列（成对迁移 000213）
- 线下申请校验启用的收款方式字典项与必填交易流水号，交易流水号独立于在线渠道交易号、不参与去重
- 扩展 offline_recharge_approval 场景可映射字段白名单与字典引用保护
- 新增付款凭证识别能力与交易流水号预填接口，识别不落库、日志不记录载荷

internal/application/wecom/scene.go

@@ -317,6 +317,10 @@ func sceneBusinessFields(businessType string) ([]dto.WeComBusinessFieldResponse,
 			{Code: constants.ApprovalFieldRemark, Name: "备注", ValueType: constants.ApprovalFieldValueTypeString, Description: "员工提交线下代充值时填写的备注"},
 			{Code: constants.ApprovalFieldSubmitterID, Name: "提交人账号 ID", ValueType: constants.ApprovalFieldValueTypeInteger, Description: "本系统真实业务提交人账号 ID"},
 			{Code: constants.ApprovalFieldSubmitterName, Name: "提交人名称", ValueType: constants.ApprovalFieldValueTypeString, Description: "本系统真实业务提交人名称快照"},
+			{Code: constants.ApprovalFieldOfflinePaymentMethod, Name: "线下收款方式", ValueType: constants.ApprovalFieldValueTypeString, Description: "本次充值使用的线下收款方式名称快照"},
+			{Code: constants.ApprovalFieldOfflinePaymentMethodCode, Name: "线下收款方式编码", ValueType: constants.ApprovalFieldValueTypeString, Description: "本次充值使用的线下收款方式稳定编码快照"},
+			{Code: constants.ApprovalFieldExternalTransactionNo, Name: "交易流水号", ValueType: constants.ApprovalFieldValueTypeString, Description: "人工确认的第三方交易流水号，用于审批人核验；与在线渠道交易号无关"},
+			{Code: constants.ApprovalFieldOtherVoucherKey, Name: "其他凭证", ValueType: constants.ApprovalFieldValueTypeFileList, Description: "提交时上传到企微文件控件的其他凭证列表"},
 		}, true
 	case constants.ApprovalBusinessTypeRefund:
 		return []dto.WeComBusinessFieldResponse{