refactor(cli): rename --power-off to --off on stop subcommand

src/cli.rs

@@ -89,7 +89,7 @@ pub enum Commands {
         cluster: String,
 
         /// Power off cluster after stopping containers (requires HA config).
-        #[arg(long, default_value = "false")]
+        #[arg(long = "off", default_value = "false")]
         power_off: bool,
     },