Minor changes

app/helpers/users/digests_helper.rb

@@ -2,9 +2,6 @@
 
 module Users
   module DigestsHelper
-    EARTH_CIRCUMFERENCE_KM = 40_075
-    MOON_DISTANCE_KM = 384_400
-
     def distance_with_unit(distance_meters, unit)
       value = Users::Digest.convert_distance(distance_meters, unit).round
       "#{number_with_delimiter(value)} #{unit}"
@@ -13,11 +10,11 @@ module Users
     def distance_comparison_text(distance_meters)
       distance_km = distance_meters.to_f / 1000
 
-      if distance_km >= MOON_DISTANCE_KM
-        percentage = ((distance_km / MOON_DISTANCE_KM) * 100).round(1)
+      if distance_km >= Users::Digest::MOON_DISTANCE_KM
+        percentage = ((distance_km / Users::Digest::MOON_DISTANCE_KM) * 100).round(1)
         "That's #{percentage}% of the distance to the Moon!"
       else
-        percentage = ((distance_km / EARTH_CIRCUMFERENCE_KM) * 100).round(1)
+        percentage = ((distance_km / Users::Digest::EARTH_CIRCUMFERENCE_KM) * 100).round(1)
         "That's #{percentage}% of Earth's circumference!"
       end
     end

app/jobs/users/digests/calculating_job.rb

@@ -21,6 +21,6 @@ class Users::Digests::CalculatingJob < ApplicationJob
       content: "#{error.message}, stacktrace: #{error.backtrace.join("\n")}"
     ).call
   rescue ActiveRecord::RecordNotFound
-    # User was deleted, nothing to notify
+    nil
   end
 end

app/jobs/users/digests/email_sending_job.rb

@@ -23,8 +23,8 @@ class Users::Digests::EmailSendingJob < ApplicationJob
 
   def should_send_email?(user, digest)
     return false unless user.safe_settings.digest_emails_enabled?
-    return false unless digest.present?
-    return false if digest.sent_at.present? # Already sent
+    return false if digest.blank?
+    return false if digest.sent_at.present?
 
     true
   end

app/models/users/digest.rb

@@ -10,15 +10,13 @@ class Users::Digest < ApplicationRecord
 
   belongs_to :user
 
-  validates :year, presence: true
-  validates :period_type, presence: true
+  validates :year, :period_type, presence: true
   validates :year, uniqueness: { scope: %i[user_id period_type] }
 
   before_create :generate_sharing_uuid
 
   enum :period_type, { monthly: 0, yearly: 1 }
 
-  # Sharing methods (following Stat model pattern)
   def sharing_enabled?
     sharing_settings.try(:[], 'enabled') == true
   end
@@ -76,8 +74,6 @@ class Users::Digest < ApplicationRecord
     )
   end
 
-  # Helper methods for accessing digest data
-  # toponyms is an array like: [{'country' => 'Germany', 'cities' => [{'city' => 'Berlin'}]}]
   def countries_count
     return 0 unless toponyms.is_a?(Array)