feat: make SSH user configurable and harden remote actions

README.md

@@ -84,6 +84,8 @@ host;display-name;action1;action2;...
 Example:
 
 ```bash README.md
+SSH_USER="root"
+
 NODES=(
   "192.168.1.10;web-01;apt;reboot"
   "192.168.1.11;db-01;apt;cmd:systemctl restart postgresql"
@@ -106,7 +108,8 @@ Options:
 
 ## Notes
 
-- SSH connections currently use `root@host`
+- SSH connections use `root@host` by default and can be changed with `SSH_USER` in the config file
+- `cmd:<remote command>` is executed through a remote shell, so shell operators such as pipes, redirections, `&&`, and `||` are supported
 - The tool is interactive and intended for manual administration workflows
 - After execution, the log file is opened with `$EDITOR` when available, otherwise with `nano`, `vi`, or `less`
 - If no supported log viewer is available, the script keeps running and prints the log file path