feat: Add Amazon SES inbound email support (#12893)

## Summary
- add AWS ActionMailbox SES gems
- document SES as incoming email provider
- note SES option in configuration

## Testing
- `bundle exec rubocop config/initializers/mailer.rb
config/environments/production.rb Gemfile`


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[Codex
Task](https://chatgpt.com/codex/tasks/task_e_68bbb7d482288326b8f04bb795af0322)

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Co-authored-by: Pranav <pranav@chatwoot.com>
Co-authored-by: Vinay Keerthi <11478411+stonecharioteer@users.noreply.github.com>

.env.example

@@ -105,6 +105,7 @@ MAILER_INBOUND_EMAIL_DOMAIN=
 # mandrill for Mandrill
 # postmark for Postmark
 # sendgrid for Sendgrid
+# ses for Amazon SES
 RAILS_INBOUND_EMAIL_SERVICE=
 # Use one of the following based on the email ingress service
 # Ref: https://edgeguides.rubyonrails.org/action_mailbox_basics.html
@@ -114,6 +115,10 @@ RAILS_INBOUND_EMAIL_PASSWORD=
 MAILGUN_INGRESS_SIGNING_KEY=
 MANDRILL_INGRESS_API_KEY=
 
+# SNS topic ARN for ActionMailbox (format: arn:aws:sns:region:account-id:topic-name)
+# Configure only if the rails_inbound_email_service = ses
+ACTION_MAILBOX_SES_SNS_TOPIC=
+
 # Creating Your Inbound Webhook Instructions for Postmark and Sendgrid:
 # Inbound webhook URL format:
 #    https://actionmailbox:[YOUR_RAILS_INBOUND_EMAIL_PASSWORD]@[YOUR_CHATWOOT_DOMAIN.COM]/rails/action_mailbox/[RAILS_INBOUND_EMAIL_SERVICE]/inbound_emails