feat: 根据 User-Agent 自动切换手机/电脑网站支付

- 新增 is_mobile_ua() 检测手机浏览器（mobile/android/iphone/ipad/harmonyos）
- build_alipay_form_html 新增 is_mobile 参数
- 手机端: alipay.trade.wap.pay + QUICK_WAP_PAY
- 桌面端: alipay.trade.page.pay + FAST_INSTANT_TRADE_PAY
- 同时应用于 payment_page 和 alipay_pay_page 两个入口

src/handlers/payment.rs

@@ -165,6 +165,17 @@ fn rsa2_verify(content: &str, sign: &str, public_key_pem: &str) -> Result<bool,
     Ok(true)
 }
 
+/// 检测是否为移动端浏览器
+fn is_mobile_ua(user_agent: &str) -> bool {
+    let ua = user_agent.to_lowercase();
+    ua.contains("mobile")
+        || ua.contains("android")
+        || ua.contains("iphone")
+        || ua.contains("ipad")
+        || ua.contains("phone")
+        || ua.contains("harmonyos")
+}
+
 // ===== Helper: 生成支付宝支付表单 HTML =====
 
 fn build_alipay_form_html(
@@ -174,12 +185,19 @@ fn build_alipay_form_html(
     subject: &str,
     notify_url: &str,
     return_url: &str,
+    is_mobile: bool,  // true=手机网站支付, false=电脑网站支付
 ) -> Result<String, String> {
+    let (method, product_code) = if is_mobile {
+        ("alipay.trade.wap.pay", "QUICK_WAP_PAY")
+    } else {
+        ("alipay.trade.page.pay", "FAST_INSTANT_TRADE_PAY")
+    };
+
     let biz_content = serde_json::json!({
         "out_trade_no": out_trade_no,
         "total_amount": total_amount,
         "subject": subject,
-        "product_code": "QUICK_WAP_PAY",
+        "product_code": product_code,
     });
 
     let biz_content_str =
@@ -188,7 +206,7 @@ fn build_alipay_form_html(
     let timestamp = chrono::Local::now().format("%Y-%m-%d %H:%M:%S").to_string();
     let mut params: BTreeMap<&str, &str> = BTreeMap::new();
     params.insert("app_id", &config.app_id);
-    params.insert("method", "alipay.trade.wap.pay");
+    params.insert("method", method);
     params.insert("format", "JSON");
     params.insert("charset", "utf-8");
     params.insert("sign_type", "RSA2");
@@ -782,6 +800,14 @@ pub async fn payment_page(
 
     let total_amount_str = format!("{:.2}", pkg.amount as f64 / 100.0);
 
+    // 根据 User-Agent 选择手机网站支付或电脑网站支付
+    let mobile = req
+        .headers()
+        .get("User-Agent")
+        .and_then(|v| v.to_str().ok())
+        .map(is_mobile_ua)
+        .unwrap_or(false);
+
     match build_alipay_form_html(
         &config,
         &order_no,
@@ -789,6 +815,7 @@ pub async fn payment_page(
         pkg.display_name,
         &notify_url,
         &return_url,
+        mobile,
     ) {
         Ok(form_html) => Ok(HttpResponse::Ok()
             .content_type("text/html; charset=utf-8")
@@ -838,6 +865,13 @@ pub async fn alipay_pay_page(
 
     let total_amount_str = format!("{:.2}", pkg.amount as f64 / 100.0);
 
+    let mobile = req
+        .headers()
+        .get("User-Agent")
+        .and_then(|v| v.to_str().ok())
+        .map(is_mobile_ua)
+        .unwrap_or(false);
+
     match build_alipay_form_html(
         &config,
         &query.order_no,
@@ -845,6 +879,7 @@ pub async fn alipay_pay_page(
         pkg.display_name,
         &notify_url,
         &return_url,
+        mobile,
     ) {
         Ok(form_html) => Ok(HttpResponse::Ok()
             .content_type("text/html; charset=utf-8")