Custom proto tool plugins.
Each tool has its own directory with a plugin.toml. The root .prototools lists the
available plugins and the versions CI installs against.
Each plugin's README has install instructions, for example:
proto plugin add prek "https://raw.githubusercontent.com/Genesis-Embodied-AI/proto-plugins/main/prek/plugin.toml"
proto pin prek latest --resolve
proto install prekSee CONTRIBUTING.md for the plugin schema, repo conventions, and how CI validates plugins.