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-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