Add setup.sh with nightly systemd timer; move key and excludes into /opt/backup

backup.sh

@@ -9,28 +9,16 @@ source "$SCRIPT_DIR/backup.env"
 # BACKUP-SPECIFIC CONFIGURATION
 # ==============================================================================
 BACKUP_LABEL="${HOSTNAME}-root"
-EXCLUDE_FILE="/etc/proxmox-backup/defaults.exclude"
-
-# Create a default exclude file if it doesn't exist
-if [ ! -f "$EXCLUDE_FILE" ]; then
-    mkdir -p "$(dirname "$EXCLUDE_FILE")"
-    cat << 'EOF' > "$EXCLUDE_FILE"
-/proc/*
-/sys/*
-/dev/*
-/run/*
-/tmp/*
-/mnt/*
-/media/*
-/lost+found
-/var/tmp/*
-/var/cache/*
-EOF
-fi
+EXCLUDE_FILE="/opt/backup/exclude"
 
 # ==============================================================================
 # EXECUTION
 # ==============================================================================
+if [ ! -f "$EXCLUDE_FILE" ]; then
+    echo "error: exclude list not found at $EXCLUDE_FILE — run setup.sh first" >&2
+    exit 1
+fi
+
 echo "Starting Proxmox Backup for ${HOSTNAME}..."
 
 EXCLUDE_ARGS=()