Under the model I propose, nostr events communicate the authoritative state and git servers provide access to the code needed create this state. Alice and Bob both claim different states for the same repository and point to different git servers. Which state does Carole see as authoritative? Maybe she knows and trusts Bob and chooses his. Maybe sees that other contributors she trusts have signed commits building on Alice's state and not Bobs so goes with Alice's.

Maybe ... I think this needs to be figured out and baked into the system. Don't leave solving the hard part to the user if that's what you head in mind.