In either case, I need a git repository initialized inside Radicale's data folder. I ran git init in /app/data/collections in the container, but subsequent commands fail with this error:

root@[app id]:/app/data/collections# git status
fatal: detected dubious ownership in repository at '/app/data/collections'
To add an exception for this directory, call:

        git config --global --add safe.directory /app/data/collections
root@[app id]:/app/data/collections# git config --global --add safe.directory /app/data/collections
error: could not lock config file /root/.gitconfig: Read-only file system
root@[app id]:/app/data/collections# git config --system --add safe.directory /app/data/collections
error: could not lock config file /etc/gitconfig: Read-only file system

I don't really want to start messing with file permissions anywhere, but then this fails too, even though it is definitely a git repository:

root@[app id]:/app/data/collections#  git config  --local -l
fatal: --local can only be used inside a git repository

Setting the flag just for that one command doesn't work either:

root@[app id]:/app/data/collections# git -c safe.directory=/app/data/collections status
fatal: detected dubious ownership in repository at '/app/data/collections'
To add an exception for this directory, call:

        git config --global --add safe.directory /app/data/collections

I was able to get everything working by logging into the host :

root@[host]:/# cd /home/yellowtent/appsdata/[app id]/data/collections
root@[host]:/home/yellowtent/appsdata/[app id]/data/collections# git status
On branch main
Untracked files:
  (use "git add <file>..." to include in what will be committed)
	[collection id]
nothing added to commit but untracked files present (use "git add" to track)

So I think I have a path forward, even though it's less than ideal. I'm just starting out with Cloudron though — is there anything I'm missing?