Show HN: db-branch – database branches in seconds for AI agents and CI, via ZFS

db-branch is an open-source tool that creates instant copy-on-write database branches for MySQL and PostgreSQL using ZFS clones, enabling fast testing, CI/CD workflows, and AI agent experimentation without duplicating data. The tool is self-hosted, currently in beta, and can be set up on a Mac or Windows machine in about 2 minutes using Ubuntu VM with Multipass, with a live demo available in the browser.