修复退款请求 funds_account 重复映射冲突，确保 V3 退款参数可正确序列化

[Copilot]

问题聚焦在 V3 退款参数 funds_account 的可用性：普通商户退款请求需要支持该字段及 amount.from 资金出资明细。当前代码中普通商户模型已具备这两个参数，但服务商退款子类对 funds_account 的重复声明会导致 Gson 序列化冲突。

• 变更摘要

  • 在 WxPayPartnerRefundV3Request 中移除重复的 fundsAccount 字段定义（保留父类 WxPayRefundV3Request 的统一定义）。
  • 保持 WxPayRefundV3Request 中 funds_account 与 Amount.from 的现有结构不变，避免接口参数语义漂移。
  • 结果是普通商户与服务商退款请求均通过同一字段映射输出 funds_account，不再触发重复 JSON 字段异常。

• 影响范围

  • weixin-java-pay 模块退款请求模型（V3）。
  • 不涉及 API 行为变更，仅修正请求对象序列化一致性与兼容性。

WxPayRefundV3Request request = new WxPayRefundV3Request();
request.setOutRefundNo("1217752501201407033233368018");
request.setFundsAccount("AVAILABLE");

WxPayRefundV3Request.From from = new WxPayRefundV3Request.From();
from.setAccount("AVAILABLE");
from.setAmount(444);

WxPayRefundV3Request.Amount amount = new WxPayRefundV3Request.Amount();
amount.setRefund(888);
amount.setTotal(888);
amount.setCurrency("CNY");
amount.setFrom(java.util.Collections.singletonList(from));
request.setAmount(amount);

[Copilot]

Pull request overview

移除 WxPayPartnerRefundV3Request 中与父类 WxPayRefundV3Request 重复定义的 fundsAccount 字段，避免 Gson 在序列化时因同一 JSON 字段 funds_account 被声明两次而冲突，统一普通商户与服务商退款请求的字段映射。

Changes:

• 删除子类中重复的 fundsAccount 字段及其 @SerializedName("funds_account") 注解，保留父类定义。

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Keep the partner fundsAccount setter ABI

Removing this field also removes Lombok's generated WxPayPartnerRefundV3Request setFundsAccount(String) method. Existing applications compiled against the previous artifact will still invoke that exact descriptor and can hit NoSuchMethodError after upgrading, because the inherited setter returns WxPayRefundV3Request instead; recompilation also breaks chains where a partner-specific setter follows setFundsAccount. Please add an explicit forwarding setter on the partner request that writes the inherited property and returns WxPayPartnerRefundV3Request, without reintroducing the duplicate serialized field.

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