feat: exit listener after successful switch for automatic restart

After a successful switch deployment, the listener now exits gracefully
so systemd can restart it with the new binary. This works together with
stopIfChanged/restartIfChanged to ensure deployments complete before
the service restarts.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/homelab-deploy/main.go

@@ -16,7 +16,7 @@ import (
 	"github.com/urfave/cli/v3"
 )
 
-const version = "0.1.4"
+const version = "0.1.5"
 
 func main() {
 	app := &cli.Command{