improve machine and ip address heartbeat querying speeds (#490)

Author: FoxMoss

db/migrate/20250821021751_add_alt_identifying_indexes.rb

@@ -0,0 +1,6 @@
+class AddAltIdentifyingIndexes < ActiveRecord::Migration[8.0]
+  def change
+    add_index :heartbeats, :ip_address
+    add_index :heartbeats, :machine
+  end
+end