tmux-ip: portable local-IP fallback for macOS

`hostname -I` is GNU-only and errors on BSD/macOS, so when the public-IP
curl couldn't reach api.ipify.org the script printed nothing and the
tmux status bar showed an empty IP. Try `ipconfig getifaddr` for common
interfaces first, fall back to `hostname -I` on Linux, then `ifconfig`
as a last resort. Also guard against empty-but-zero-exit curl output.

.local/bin/tmux-ip

@@ -29,5 +29,21 @@ if is_digitalocean && do_anchor_ip; then
   exit 0
 fi
 
-curl -s --connect-timeout 3 https://api.ipify.org 2>/dev/null \
+print_local_ip() {
-  || hostname -I | awk '{print $1}'
+  local iface ip
+  if command -v ipconfig >/dev/null 2>&1; then
+    for iface in en0 en1 en2; do
+      ip=$(ipconfig getifaddr "$iface" 2>/dev/null) || true
+      [ -n "${ip:-}" ] && { printf '%s\n' "$ip"; return 0; }
+    done
+  fi
+  if hostname -I >/dev/null 2>&1; then
+    hostname -I | awk '{print $1}'
+    return 0
+  fi
+  ifconfig 2>/dev/null | awk '/inet /{ if ($2 != "127.0.0.1") { print $2; exit } }'
+}
+
+ip=$(curl -s --connect-timeout 3 https://api.ipify.org 2>/dev/null || true)
+[ -z "${ip:-}" ] && ip=$(print_local_ip)
+printf '%s\n' "${ip:-}"