Add kredits API with wallet balance endpoint

config/routes.rb

@@ -25,6 +25,10 @@ Rails.application.routes.draw do
   get 'lnurlpay/:address', to: 'lnurlpay#index', constraints: { address: /[^\/]+/}
   get 'lnurlpay/:address/invoice', to: 'lnurlpay#invoice', constraints: { address: /[^\/]+/}
 
+  namespace :api do
+    get 'kredits/onchain_btc_balance', to: 'kredits#onchain_btc_balance'
+  end
+
   namespace :admin do
     root to: 'dashboard#index'
     get 'invitations', to: 'invitations#index'