Ability to set SQLite backup location

Hi, thanks for the great work on Vaultwarden! I'm just getting started with it, and while setting up my backup scripts, I ran into a small issue that could be addressed It would be useful to have an option to configure a custom directory for SQLite backups, for example, through a new BACKUP_FOLDER environment variable Currently, the /vaultwarden backup command saves the backup in the data directory. This makes it a bit difficult to use in automated backup scripts, as the command output is not particularly convenient to work with programmatically For example, my current backup script looks like this: The script needs to parse the command output to determine the backup filename and then move the generated file out of the data directory before passing it to the backup process The command currently prints a message like Backup to 'data/db_20261013_112233.sqlite3' was successful, which is not really convenient for automation, as scripts need to extract the…