fix: improve email activation error handling

- Add logging for successful email delivery
- Implement error handling for email sending failures
- Raise exceptions for further handling

This change improves the robustness of the email activation
process by logging outcomes and handling potential errors,
allowing for better debugging and monitoring of email
notifications.

app/models/user.rb

@@ -64,7 +64,14 @@ class User < ApplicationRecord
   end
 
   def send_activation_email
-    UserMailer.account_activation(self).deliver_now
+    begin
+      result = UserMailer.account_activation(self).deliver_now
+      Rails.logger.info "Email sent successfully: #{result.inspect}"
+    rescue => e
+      Rails.logger.error "Failed to send email: #{e.message}"
+      Rails.logger.error e.backtrace.join("\n")
+      raise
+    end
   end
 
   def create_reset_digest