* snowshare: use mv instead of cp for uploads backup to prevent disk fill
Replaces cp -a with mv when backing up and restoring /opt/snowshare/uploads
during updates. cp -a duplicated the entire uploads directory on each update,
which could fill the disk on instances with large uploads and left stale
backup directories accumulating across failed updates. mv is atomic on the
same filesystem and avoids any data duplication. Also clears any leftover
backup directory before the move to prevent nesting on interrupted updates.
Refs TuroYT/snowshare#258
* snowshare: use UPLOAD_DIR env to persist uploads outside install dir
Set UPLOAD_DIR=/opt/snowshare_data in the env file so uploads live
outside /opt/snowshare and survive CLEAN_INSTALL updates without any
backup/restore step. Existing installations are migrated on first
update by moving uploads to the new location and appending UPLOAD_DIR
to the env file, making the change non-breaking.
Romain PINSOLLE