feat: add wob overlay for volume and brightness keys

Move FIFO setup and percentage emission into helper scripts so the
Hyprland config has no raw $VAR references — Hyprland's parser
substitutes $varname at parse time, which mangled awk's $2 and
$HYPRLAND_INSTANCE_SIGNATURE and left binds broken after reload.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

hypr/scripts/wob-brightness.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+# Adjust backlight and emit current percentage to the wob overlay FIFO.
+# Usage: wob-brightness.sh up|down
+
+set -u
+
+case "${1:-}" in
+    up)   brightnessctl -e4 -n2 set 5%+ >/dev/null ;;
+    down) brightnessctl -e4 -n2 set 5%- >/dev/null ;;
+    *)    echo "usage: $0 up|down" >&2; exit 2 ;;
+esac
+
+fifo="${XDG_RUNTIME_DIR:-/tmp}/hypr-wob.${HYPRLAND_INSTANCE_SIGNATURE:-default}"
+[[ -p "$fifo" ]] || exit 0
+current=$(brightnessctl get)
+max=$(brightnessctl max)
+awk -v c="$current" -v m="$max" 'BEGIN { printf "%d\n", (c/m)*100 }' > "$fifo"

hypr/scripts/wob-daemon.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+# Run by Hyprland exec-once. Creates a per-instance FIFO and pipes it to wob
+# so volume/brightness binds can show an on-screen overlay.
+
+set -u
+
+command -v wob >/dev/null 2>&1 || exit 0
+
+fifo="${XDG_RUNTIME_DIR:-/tmp}/hypr-wob.${HYPRLAND_INSTANCE_SIGNATURE:-default}"
+rm -f "$fifo"
+mkfifo "$fifo"
+trap 'rm -f "$fifo"' EXIT
+
+tail -f "$fifo" | wob

hypr/scripts/wob-volume.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+# Adjust volume and emit current percentage to the wob overlay FIFO.
+# Usage: wob-volume.sh up|down
+
+set -u
+
+case "${1:-}" in
+    up)   wpctl set-volume -l 1 @DEFAULT_AUDIO_SINK@ 5%+ ;;
+    down) wpctl set-volume @DEFAULT_AUDIO_SINK@ 5%- ;;
+    *)    echo "usage: $0 up|down" >&2; exit 2 ;;
+esac
+
+fifo="${XDG_RUNTIME_DIR:-/tmp}/hypr-wob.${HYPRLAND_INSTANCE_SIGNATURE:-default}"
+[[ -p "$fifo" ]] || exit 0
+wpctl get-volume @DEFAULT_AUDIO_SINK@ | awk '{printf "%d\n", $2*100}' > "$fifo"