Notifuse/notifuse ? reverse-engineered prompt

Build me a modern self hosted emailing platform like a simpler open source Mailchimp and transactional email tool in one.

I want a web app where I can manage contacts, create lists, segment subscribers, and send newsletters and one off transactional emails. It should have a clean admin console for campaigns, a drag and drop email builder with real time preview, basic A B testing, and a dashboard that shows opens, clicks, delivery, and other important stats. I also want a developer friendly API for sending emails from my app, plus webhooks for email events.

Please include support for common email providers like SMTP and popular delivery services, a setup flow that makes it easy to get started, and a notification center widget I can embed in another product. Use a modern Go backend and a React based frontend, and make it easy to run locally with Docker. If anything is unclear, look up the current docs online and match the project style.