tmux-ip: prefer DigitalOcean reserved/floating IP when on a droplet

If /sys/class/dmi/id/sys_vendor says DigitalOcean and the droplet has
a reserved_ip or floating_ip assigned, use that over the ipify-based
egress IP. Keeps the ipify/hostname -I fallback intact for other hosts.

Gated on the DMI check so non-DO hosts skip the metadata probe entirely
and the tmux status bar refresh stays fast.

.local/bin/tmux-ip

@@ -1,2 +1,33 @@
 #!/bin/bash
-curl -s --connect-timeout 3 https://api.ipify.org 2>/dev/null || hostname -I | awk '{print $1}'
+#
+# Print the "best" IP for the tmux status bar.
+# Preference: DO reserved/floating IP > public egress (ipify) > first local IP.
+#
+
+set -u
+
+META="http://169.254.169.254/metadata/v1"
+CURL="curl -sf --connect-timeout 1 --max-time 2"
+
+is_digitalocean() {
+  [ -r /sys/class/dmi/id/sys_vendor ] \
+    && grep -qi digitalocean /sys/class/dmi/id/sys_vendor
+}
+
+do_anchor_ip() {
+  local kind active ip
+  for kind in reserved_ip floating_ip; do
+    active=$($CURL "$META/$kind/ipv4/active" 2>/dev/null) || continue
+    [ "$active" = "true" ] || continue
+    ip=$($CURL "$META/$kind/ipv4/address" 2>/dev/null) || continue
+    [ -n "$ip" ] && { printf '%s\n' "$ip"; return 0; }
+  done
+  return 1
+}
+
+if is_digitalocean && do_anchor_ip; then
+  exit 0
+fi
+
+curl -s --connect-timeout 3 https://api.ipify.org 2>/dev/null \
+  || hostname -I | awk '{print $1}'