Stopping charge at 80% (and still going down near 0%) should give you roughly 4x the cycle life. So in theory doing that it would take about 8 years to hit the same 85% usable level.
85% left after 2.5 years is a high rate of wear, due to phones really pushing as much as they can into the battery to have longer run times.
Owncloud supports selective sync, and seems a lot better for performance compared to Nextcloud.
Alternatively you could roll your own with rclone which is essentially an open source alternative to mountain duck. Then you can just use a simple connection via SFTP, FTP, WebDAV, etc…
That sounds normal, server linux has no GUI/Desktop, only a console.
To get a full CLI that you can select/copy/paste in you just need to SSH in, instead of using the Proxmox console.
The proxmox console is meant for rare usage like installing the OS and recovering from failures, it’s not meant to be used as a daily way to interact with the VMs.
Did you change the mysql container database name, username and password to something other than the default linguacafe ?
That would break it, as it’s using those specific credentials to login to the database. Which would cause Access denied for user ‘linguacafe’@‘ip adress censored’ (using password: YES) (SQL: select count(*) as aggregate from users)
Try with the default, you’ll need to wipe the mysql data under /home/user/Documents/Docker/LinguaCafe/database/ after stopping the container first.