feat: airplane mode (#104) + crisper fastfetch logo (#122)

Airplane: runtime Wi-Fi+Bluetooth kill-switch with prior-state restore,
System menu + SUPER+CTRL+R, Waybar plane glyph (self-hides, whole-swap
parity). Fastfetch: chafa sextants at 24×12 (was block 20×10) for a
finer monogram; V2 kitty screenshots under boreal and summer-night.

themes/executive-slate/waybar.css

@@ -71,6 +71,7 @@ window#waybar {
 #custom-recording,
 #idle_inhibitor,
 #custom-nightlight,
+#custom-airplane,
 #language,
 #custom-updates,
 #pulseaudio,
@@ -148,6 +149,7 @@ window#waybar {
 #idle_inhibitor.activated   { color: @warn; }
 
 #custom-nightlight.on        { color: @warn; }
+#custom-airplane.on        { color: @warn; }
 
 #custom-updates.available    { color: @accent; }
 
@@ -157,6 +159,7 @@ window#waybar {
    neighbours. */
 #custom-recording,
 #custom-nightlight,
+#custom-airplane,
 #custom-updates,
 #custom-vpn,
 #custom-doctor,