Switch Minecraft server to FTB StoneBlock 4 (name + modpack metadata)

config.json, discordBot.js, serverUpdates.js and ServerCard.jsx updated from Biohazard to FTB StoneBlock 4. Docs (infrastructure/gsm/CLAUDE) updated and docs/minecraft-modpack-install.md added. No Discord update notification is triggered (minecraft supportsUpdate=false).

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

docs/gsm.md

@@ -190,7 +190,7 @@ Frontend    Backend
   "servers": [
     {
       "id": "minecraft",
-      "name": "Biohazard: Project Genesis | Minecraft",
+      "name": "FTB StoneBlock 4 | Minecraft",
       "host": "192.168.2.51",
       "type": "minecraft",
       "runtime": "screen",