Static dev domains for all ngrok users

Ngrok has updated its service offerings by introducing free dev domains to address user complaints regarding changing URLs with each agent restart. Every ngrok account now includes a free dev domain based on the ngrok-free.dev base, which remains assigned to the user as long as their account is active. This change simplifies the development and testing lifecycle by offering a consistent domain for applications and APIs, without incurring additional endpoint hour charges. Users have the option to upgrade to paid plans for custom or branded domains, with the Hobbyist plan allowing custom ngrok domains and the pay-as-you-go plan enabling users to bring their own domains. Ngrok's goal is to provide developers with an infrastructure that simplifies the process of putting APIs and apps online. The dev domains facilitate easier application deployment, with various integration options such as cloud endpoints, the ngrok agent SDK, and Kubernetes clusters, while maintaining usage limits on free plans for HTTP requests, bandwidth, and concurrent endpoints.