Fix unquoted variables in all shell scripts to prevent word splitting

Co-authored-by: andrejusk <7396847+andrejusk@users.noreply.github.com>

script/install.d/01-ssh.sh

@@ -18,14 +18,14 @@ if [ -z "$SKIP_SSH_CONFIG" ]; then
     ssh_target="${HOME}/.ssh"
     ssh_key="${ssh_target}/id_${ssh_method}"
     ssh_pub="${ssh_key}.pub"
-    if [ ! -f $ssh_key ]; then
+    if [ ! -f "$ssh_key" ]; then
         ssh-keygen \
-            -t $ssh_method \
-            -f $ssh_key \
+            -t "$ssh_method" \
+            -f "$ssh_key" \
             -C "$(whoami)@$(hostname)-$(date -I)"
     fi
 
-    cat $ssh_pub
+    cat "$ssh_pub"
 
     unset ssh_method ssh_target ssh_key ssh_pub
 else