feat(hyprland): add airplane-mode waybar toggle

I added a laptop-only waybar button that drops the machine into a low-power state and restores it on a second click. Engaging turns wifi off, sets the CPU energy-performance preference to power, dims the backlight to 35%, and stops network-only services (tailscale, proton-vpn, avahi, cups, wsdd, geoclue, sshd, fail2ban, syncthing). Bluetooth is left alone so earbuds keep working.

Disengaging replays the state recorded when airplane mode was engaged rather than writing hardcoded defaults. A lever already in its low-power position is left untouched: wifi that was already off stays off, and a service that was already stopped isn't restarted.

The indicator hides itself on machines with no battery, so desktops never show the button. State lives in $XDG_RUNTIME_DIR/airplane-state, and the bar refreshes the moment the toggle fires via a realtime signal.

1 files changed, 33 insertions, 0 deletions

diff --git a/dotfiles/hyprland/.local/bin/waybar-airplane b/dotfiles/hyprland/.local/bin/waybar-airplane
new file mode 100755
index 0000000..21f869c
--- /dev/null
+++ b/dotfiles/hyprland/.local/bin/waybar-airplane
@@ -0,0 +1,33 @@
+#!/bin/sh
+# Airplane-mode indicator for waybar.
+# Reads the state file the airplane-mode toggle maintains; emits one JSON line
+# (text + tooltip + class) for the custom/airplane module. The file holds
+# key=value lines; only `mode` (on/off) matters here. Anything other than
+# "on" reads as off, so a missing or garbled state file fails safe (airplane
+# mode shown as inactive — i.e. radios assumed on).
+#
+# Laptop-only: airplane mode is meaningless on a desktop, so the module hides
+# itself (emits nothing → waybar drops it) on machines with no battery.
+
+STATE_FILE="${XDG_RUNTIME_DIR:-/tmp}/airplane-state"
+PS_DIR="${AIRPLANE_POWER_SUPPLY_DIR:-/sys/class/power_supply}"
+
+# Laptop check: a battery present means this is a portable machine.
+is_laptop() {
+    for b in "$PS_DIR"/BAT*; do
+        [ -e "$b" ] && return 0
+    done
+    return 1
+}
+
+is_laptop || exit 0
+
+mode=$(sed -n 's/^mode=//p' "$STATE_FILE" 2>/dev/null | head -n1)
+
+# Same clear plane glyph in both states; the class drives the color (gold when
+# engaged, default gray when not) so there's no slash to obscure the wings.
+if [ "$mode" = "on" ]; then
+    echo "{\"text\": \"<span size='large'></span>\", \"tooltip\": \"Airplane mode ON — wifi off, low power\", \"class\": \"active\"}"
+else
+    echo "{\"text\": \"<span size='large'></span>\", \"tooltip\": \"Airplane mode OFF\", \"class\": \"inactive\"}"
+fi