feat(waybar): remove system tray module

Drops 'tray' from modules-right and its config block. Network and
bluetooth status remain as their own dedicated modules.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

waybar/config.jsonc

@@ -14,7 +14,6 @@
     "network",
     "bluetooth",
     "battery",
-    "tray",
   ],
   "cpu": {
     "format": "  {usage}%",
@@ -72,10 +71,6 @@
     },
   },
 
-  "tray": {
-    "spacing": 8,
-  },
-
   "network": {
     "format-wifi": "  {essid}",
     "format-ethernet": "󰈀",