TwiN/gatus ? reverse-engineered prompt

I want to build a self-hosted status page application. It should be a single dashboard that I can use to monitor all of my websites and services.

The main function is to perform health checks. It should be able to check standard HTTP endpoints, but also lower-level stuff like ICMP pings, TCP ports, and even DNS queries. For each service, I want to define conditions for what counts as "healthy," like checking for a 200 status code, a response time under 500ms, or that an SSL certificate isn't about to expire.

The dashboard needs to look clean and modern, showing the current status of each service, its historical uptime, and a response time graph. The most important feature is alerting. If a service goes down, I need it to send a notification to Slack, PagerDuty, Discord, or maybe even send an SMS via Twilio. Let's make it configurable with a simple YAML file and build it in Go so it's a single, easy-to-deploy binary, preferably in a Docker container.