Add LndHub db/models, and quick stats for admin views

app/controllers/admin/lightning_controller.rb

@@ -0,0 +1,12 @@
+class Admin::LightningController < Admin::BaseController
+  def index
+    @current_section = :lightning
+
+    @users = User.pluck(:cn, :ou, :ln_account)
+    @accounts = LndhubAccount.with_balances.order(balance: :desc).to_a
+
+    @ln = {}
+    @ln[:current_balance] = LndhubAccount.current.joins(:ledgers).sum("account_ledgers.amount")
+    @ln[:users_with_sats] = @accounts.length
+  end
+end