CP-11289 - Fix rubocop issues

app/services/document_security_service.rb

@@ -47,15 +47,15 @@ class DocumentSecurityService
     end
 
     def cloudfront_base_url
-      @cloudfront_base_url ||= ENV['CF_URL']
+      @cloudfront_base_url ||= ENV.fetch('CF_URL', nil)
     end
 
     def cloudfront_key_pair_id
-      @cloudfront_key_pair_id ||= ENV['CF_KEY_PAIR_ID']
+      @cloudfront_key_pair_id ||= ENV.fetch('CF_KEY_PAIR_ID', nil)
     end
 
     def cloudfront_private_key
-      @cloudfront_private_key ||= ENV['SECURE_ATTACHMENT_PRIVATE_KEY']
+      @cloudfront_private_key ||= ENV.fetch('SECURE_ATTACHMENT_PRIVATE_KEY', nil)
     end
   end
 end

config/initializers/secure_attachment.rb

@@ -4,7 +4,7 @@ require 'aws-sdk-secretsmanager'
 
 # Load CloudFront private key from AWS Secrets Manager (same as ATS)
 # Configuration loaded from environment variables (set in cpdocuseal deployment)
-key_secret = ENV['CF_KEY_SECRET']
+key_secret = ENV.fetch('CF_KEY_SECRET', nil)
 
 if key_secret.present?
   begin