fix: disable email transcript for free plans (#13509)

- Block email transcript functionality for accounts without a paid plan
to prevent SES abuse.

app/models/concerns/account_email_rate_limitable.rb

@@ -12,6 +12,10 @@ module AccountEmailRateLimitable
     Redis::Alfred.get(email_count_cache_key).to_i
   end
 
+  def email_transcript_enabled?
+    true
+  end
+
   def within_email_rate_limit?
     return true if emails_sent_today < email_rate_limit