User can unlock file locked by other user in shared folders

Scenario:
User A creates a shared directory.
User B creates a file in that directory and locks the file
User A tries to unlock that file.

What happens:
The file gets unlocked without errors.

What should happen / is expected:
The file stays locked and the server returns 403. Because the lock is owned by user B.

Why does this happen
The initial test if the owner of the lock and the current user are the same, fails ✔️
https://github.com/nextcloud/files_lock/blob/7b1827af32b848b6ed25bcefc17696b9260a61f8/lib/Service/LockService.php#L244

But then the next check allows to unlock, because the file is created inside the shared directory it is owned implicitly by the sharing user, and we allow file owners always to unlock:
https://github.com/nextcloud/files_lock/blob/7b1827af32b848b6ed25bcefc17696b9260a61f8/lib/Service/LockService.php#L248

I am not sure if this is a feature or a bug. So probably two solutions here:

1. Allow configure whether file owners are allowed to always unlock
2. Document that file owners always can unlock their files and note that files in shared folders are always owned by the folder owner.

Start in lib/Service/LockService.php at the checks around lines 244 and 248, then trace the unlock request and its existing tests. Confirm how ownership is determined for files in shared directories and decide whether the intended behavior is a 403 response or a documented/configurable exception. Done means the chosen policy is covered by a regression test and the reported scenario behaves accordingly.