The word on vendoring is https://github.com/mholt/caddy/issues/200#issuecomment-164170670. caddy is kind of a pain because addons need to be included at compile time, and they have a build server in order to serve the gazillions of combinations you can download on https://caddyserver.com/download. I guess it'd be a lot of work to have vendored dependencies work on their server.
caddy 0.9.5
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Created with `brew bump-formula-pr`.
googler is GPL licensed (*NOT* AGPL). That should answer your question.
https://www.google.com/search?q=gpl+proprietary+web+app