prompt user for hub hostname with oily.dad as default

spoke/setup-spoke.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-HUB_HOST="oily.dad"
+HUB_HOST=""
 HUB_USER="armbian"
 ARMBIAN_HOME="/home/armbian"
 SSH_DIR="$ARMBIAN_HOME/.ssh"
@@ -42,6 +42,9 @@ header() { echo -e "\n${CYAN}═════════════════
 
 [ "$(id -u)" -eq 0 ] || die "Run as root"
 
+read -rp "Hub hostname [oily.dad]: " HUB_HOST
+HUB_HOST="${HUB_HOST:-oily.dad}"
+
 header "TinyBoard Spoke Setup"
 
 info "Installing packages..."