Apparently git let’s you push two completely independent histories into one repo if you force push and will happily let you go about your business until you try to merge.
I found this out when an intern copied the code, initiated a new repo, worked off that repo, force pushed into remote, kept working on his branches. Absolutely not his fault, he should have had help. But I had to edit history and rewrite the parent of a commit to unite the family lines!
Fun to learn that you can create that problem and also there’s a “way” to fix it.
Just to clarify the entire Logseq app is open source including the sync mechanism, the server backend to receive the sync endpoint and store the data isn’t. I use Syncthing (FOSS and cross platform) to sync noted between my devices.