Add kredits API with wallet balance endpoint

app/controllers/api/base_controller.rb

@@ -0,0 +1,5 @@
+class Api::BaseController < ApplicationController
+
+  layout false
+
+end

app/controllers/api/kredits_controller.rb

@@ -0,0 +1,12 @@
+class Api::KreditsController < Api::BaseController
+
+  def onchain_btc_balance
+    btcpay = BtcPay.new
+    balance = btcpay.onchain_wallet_balance
+    render json: balance
+  rescue
+    render json: { error: 'Failed to fetch wallet balance' },
+           status: 500
+  end
+
+end

app/services/btc_pay.rb

@@ -9,12 +9,12 @@ class BtcPay
   end
 
   def onchain_wallet_balance
-    wallet_info = get "stores/#{@store_id}/payment-methods/onchain/BTC/wallet"
+    res = get "stores/#{@store_id}/payment-methods/onchain/BTC/wallet"
 
     {
-      balance: wallet_info["balance"].to_f,
-      unconfirmed_balance: wallet_info["unconfirmedBalance"].to_f,
-      confirmed_balance: wallet_info["confirmedBalance"].to_f
+      balance: res["balance"].to_f,
+      unconfirmed_balance: res["unconfirmedBalance"].to_f,
+      confirmed_balance: res["confirmedBalance"].to_f
     }
   end