The version of gptr's public extension API (independent of the package version) and the
features this build offers: kind.<name> for every registered kind, event.<name> for every
cataloged event, and the named features lazy_activation, declarations, ctx.decide,
ctx.secret, route and services. Plugins test features instead of comparing versions.
Examples
gptr_api()$version
#> [1] ‘1.0’
"kind.router" %in% gptr_api()$features
#> [1] TRUE