Add Hytale server support with tmux runtime

- Add tmux runtime support to ssh.js (status, start, stop, logs, uptime)
- Add Hytale server configuration to config.json
- Add Hytale server info and logo to frontend (ServerCard, ServerDetail)
- Add Hytale emoji to Discord notification mapping
- Update documentation with Hytale server details

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

gsm-backend/routes/servers.js

@@ -841,7 +841,7 @@ router.post("/discord/send-update", authenticateToken, requireRole("superadmin")
   try {
     const serverIcons = {
       minecraft: '⛏️', factorio: '⚙️', zomboid: '🧟', vrising: '🧛',
-      palworld: '🦎', terraria: '⚔️', openttd: '🚂'
+      palworld: '🦎', terraria: '⚔️', openttd: '🚂', hytale: '🏰'
     };
 
     const embed = new EmbedBuilder()