Tidy up homepage and navigation

app/models/network_range.rb

@@ -29,6 +29,8 @@ class NetworkRange < ApplicationRecord
   scope :vpn, -> { where(is_vpn: true) }
   scope :user_created, -> { where(source: 'user_created') }
   scope :api_imported, -> { where(source: 'api_imported') }
+  scope :with_events, -> { where("events_count > 0") }
+  scope :most_active, -> { order(events_count: :desc) }
 
   # Callbacks
   before_validation :set_default_source
@@ -237,9 +239,10 @@ class NetworkRange < ApplicationRecord
     cidr.to_s.gsub('/', '_')
   end
 
-  # Analytics methods
+  # Analytics methods - events_count is now a counter cache column maintained by database triggers
+  # This is much more performant than the previous implementation that did complex network queries
   def events_count
-    Event.where(ip_address: child_ranges.pluck(:network_address) + [network_address]).count
+    self[:events_count] || 0
   end
 
   def recent_events(limit: 100)