fix: 退款回调同步使用手动表单解析避免GBK编码问题

src/handlers/payment.rs

@@ -1057,9 +1057,9 @@ pub async fn payment_success(
 #[post("/payment/refund-notify")]
 pub async fn alipay_refund_notify(
     pool: web::Data<PgPool>,
-    body: web::Form<BTreeMap<String, String>>,
+    body_bytes: web::Bytes,
 ) -> HttpResponse {
-    let body = body.into_inner();
+    let body = parse_alipay_form(&body_bytes);
 
     let out_trade_no = body.get("out_trade_no").cloned().unwrap_or_default();
     let refund_status = body.get("refund_status").cloned().unwrap_or_default();