refactor: 支付链路规范化 — 统一命名/层次/传参

- ISDKHelper.pay() 增加 productPrice 参数，与 UnityKnowNew 签名对齐
- FlexionSDKHelper: prodPrice/prodCount 从参数直接写入 developerPayload
- playerId → userId 统一命名 (SDKTest/Java payload)
- pfId → pfid 统一小写 (服务端 JSON key)
- PaymentInfo 序列化替代 StringBuilder 手拼 JSON
- FlexionPaymentVerifier.Consume 走 UnityBridgeFunc.ConsumePurchase 桥接层
- UnityBridgeFunc 新增 ConsumePurchase 通用方法，移除渠道特定方法
- SDKManager.ConsumeFlexionPurchase → ConsumePurchase 通用化

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ExtraPluginCfgs/Android/flexion/FlexionSDKHelper.java

@@ -88,8 +88,9 @@ public class FlexionSDKHelper implements SDKManager.ISDKHelper {
     }
 
     @Override
-    public void pay(Activity activity, String productId, String productName,
-                    String productCount, String prodorderId, String appInfo) {
+    public void pay(Activity activity, String productId, String productPrice,
+                    String productName, String productCount, String prodorderId,
+                    String appInfo) {
         Log.i(TAG, "[PAY-FLOW] pay called: productId=" + productId + " billingReady=" + billingConnected);
         if (billingService == null || !billingConnected) {
             Log.e(TAG, "[PAY-FLOW] billing not ready");
@@ -101,11 +102,14 @@ public class FlexionSDKHelper implements SDKManager.ISDKHelper {
             byte[] decoded = Base64.getDecoder().decode(appInfo);
             JSONObject json = new JSONObject(new String(decoded, "UTF-8"));
             JSONObject payload = new JSONObject();
-            payload.put("playerId", json.optString("playerId", ""));
+            payload.put("userId", json.optString("userId", ""));
+            payload.put("pfid", json.optString("pfid", ""));
             payload.put("customData", json.optString("customData", ""));
+            payload.put("prodPrice", productPrice);
+            payload.put("prodCount", productCount);
             developerPayload = payload.toString();
         } catch (Exception e) {
-            Log.w(TAG, "Failed to extract playerId/customData from appInfo: " + e.getMessage());
+            Log.w(TAG, "Failed to extract payload fields from appInfo: " + e.getMessage());
         }
         String finalPayload = developerPayload;
         activity.runOnUiThread(() -> {