Add swipe-down aux screen (SOCKTOP_AUX_CMD)

A separate tmux window running any TUI, reached with a vertical swipe from
any carousel screen; swiping up returns to the exact window/zoom you left.
The aux window is excluded from the horizontal carousel and horizontal
swipes on it are inert. Bound only when SOCKTOP_AUX_CMD is set.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

config.env

@@ -31,6 +31,12 @@ SOCKTOP_GROUPS="${SOCKTOP_GROUPS:-rpi-master rpi-worker-1 rpi-worker-2 rpi-worke
 # Legacy single-group form. Used only when SOCKTOP_GROUPS is empty.
 SOCKTOP_HOSTS="${SOCKTOP_HOSTS:-}"
 
+# Optional "aux" screen: a different TUI reached by swiping DOWN from any
+# carousel screen; swiping UP returns to exactly the screen you left. It runs in
+# its own tmux window, kept alive like the socktop panes, so switching is
+# instant. Leave empty to disable. Use full paths -- i3 has no ~/.cargo/bin.
+SOCKTOP_AUX_CMD="${SOCKTOP_AUX_CMD:-$HOME/.cargo/bin/uptime-kuma-status https://status.wittyoneoff.com/status/wittyoneoff}"
+
 # tmux session name. Change only if it collides with something else.
 SOCKTOP_SESSION="${SOCKTOP_SESSION:-socktop4}"
 
@@ -78,3 +84,8 @@ FINGER_COUNTS="${FINGER_COUNTS:-1 2 3}"
 # Swap these two values to reverse the direction of travel.
 GESTURE_IN="${GESTURE_IN:-RL}"
 GESTURE_OUT="${GESTURE_OUT:-LR}"
+
+# Aux screen swipes. UD = up-to-down (swipe down) shows it; DU = down-to-up
+# (swipe up) returns. Only bound when SOCKTOP_AUX_CMD is set.
+GESTURE_AUX_IN="${GESTURE_AUX_IN:-UD}"
+GESTURE_AUX_OUT="${GESTURE_AUX_OUT:-DU}"