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

app/controllers/admin/donations_controller.rb

@@ -5,7 +5,11 @@ class Admin::DonationsController < Admin::BaseController
   # GET /donations
   # GET /donations.json
   def index
-    @donations = Donation.all
+    @donations = Donation.all.order('created_at desc')
+    @stats = {
+      overall_sats: @donations.all.sum("amount_sats"),
+      donor_count: Donation.distinct.count(:user_id)
+    }
   end
 
   # GET /donations/1