fix(install): ignore chown error in unprivileged containers

misc/install.func

@@ -81,8 +81,9 @@ setting_up_container() {
   msg_info "Setting up Container OS"
 
   # Fix Debian 13 LXC template bug where / is owned by nobody
+  # Only attempt in privileged containers (unprivileged cannot chown /)
   if [[ "$(stat -c '%U' /)" != "root" ]]; then
-    chown root:root /
+    chown root:root / 2>/dev/null || true
   fi
 
   for ((i = RETRY_NUM; i > 0; i--)); do