refactor: unify Waybar configuration using Nix and fix legacy paths

config/waybar/config.jsonc

@@ -40,7 +40,7 @@
     }
   },
   "custom/nomarchy": {
-    "format": "<span font='nomarchy'>\ue900</span>",
+    "format": "<span font='nomarchy'>a</span>",
     "on-click": "nomarchy-menu",
     "on-click-right": "xdg-terminal-exec",
     "tooltip-format": "Nomarchy Menu\n\nSuper + Alt + Space"
@@ -150,7 +150,7 @@
   },
   "custom/notification-silencing-indicator": {
     "on-click": "nomarchy-toggle-notification-silencing",
-    "exec": "$OMARCHY_PATH/default/waybar/indicators/notification-silencing.sh",
+    "exec": "~/.config/nomarchy/default/waybar/indicators/notification-silencing.sh",
     "signal": 10,
     "return-type": "json"
   },