feat: merge rustore test UI and unify SKU format across channels

- Merge VK login/link/check and Review test buttons from dev_rustore
- Unify Rustore/GooglePlay SKU format via ChannelHelpers.normalizeSkuList()
- Fix ChannelConfig runtime sync: Java InitSDK sets channel from ChannelHelpers.CHANNEL
- Fix AndroidMinSdkVersion 25→26 for tuyoosdk compatibility
- Fix Flexion AndroidManifest tools:replace missing fullBackupContent value
- Add [CHANNEL-VERIFY] debug logs for channel verification

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

sdk-intergration/Packages/tysdk/Runtime/TYSdkModel.cs

@@ -94,17 +94,11 @@ namespace tysdk
         public string price_currency_code;
         public string title;
         public string type;
-
-        // RuStore specific
         public string currency;
         public string price_amount;
 
-        public string ProdPriceStr => ChannelConfig.Channel == "Rustore"
-            ? $"₽{ProdPrice}"
-            : price;
-        public float ProdPrice => ChannelConfig.Channel == "Rustore"
-            ? float.Parse(price) / 100
-            : float.Parse(price_amount_micros) / 1000000;
+        public string ProdPriceStr => price;
+        public float ProdPrice => float.Parse(price_amount_micros) / 1000000;
         public string ProdID => ourProductId;
         public string ProdKey => productId;