fix(waybar): mic icon centering and change to event-driven updating

.config/waybar/scripts/micmute.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+print_icon() {
+  if wpctl get-volume @DEFAULT_AUDIO_SOURCE@ | grep -q MUTED; then
+    echo ""
+  else
+    echo ""
+  fi
+}
+
+# Print once on startup
+print_icon
+
+# Subscribe to PipeWire events
+wpctl subscribe @DEFAULT_AUDIO_SOURCE@ | while read -r _; do
+  print_icon
+done
+