Update
Run the installer again after getting a new version:
packaging/install.sh
It reads its earlier settings first, rebuilds, and restarts the service. It never touches an existing data folder: your library and paired phones stay as they are. A migration to a new version backs up the database first.
After a Node.js major upgrade (from 26 to 27, say), run the installer again too: the server's database module is built for the Node it was installed with.
Uninstall
packaging/uninstall.sh
It removes the service and keeps every photo and setting.