Nice work. I really like the idea of song - lightweight git server without PRs and Issues to support nip34 repos. The matching aesthetic of a minimalist UI is great.

Using nostr events as authorisation for updates is really good. AUTH events aren't shared beyond the user and relay. This doesn't allow other contributors to confirm the new commits came from that npub. What if the repo event included a references to the latest branch tip and this was used as aruhoriastion instead?

That way git pull could also validate the commit was approved by the npub.