Fix Hytale prometheus metrics and config editor syntax highlighting

- Add missing "hytale" entry to SERVER_JOBS in prometheus.js
- Fix config editor regex bug that was corrupting CSS class names (e.g. text-cyan-400 becoming text-cyan-<span>400</span>)
- Use placeholder tokens to prevent numbers regex from matching inside already-replaced spans

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

gsm-backend/services/prometheus.js

@@ -9,7 +9,8 @@ const SERVER_JOBS = {
   "zomboid": "zomboid",
   "palworld": "palworld",
   "terraria": "terraria",
-  "openttd": "openttd"
+  "openttd": "openttd",
+  "hytale": "hytale"
 };
 
 export async function queryPrometheus(query) {