v2.4.3: Replace Discord links with Community Chat & Telegram

Discord server was DMCA'd. All Discord links replaced with:
- Community Chat (Stoat): chat.sanhost.net
- Telegram Channel: @hf2p_og
- Telegram Group: @sanhostnet

Launcher UI: added community links on main screen, renamed
Discord nav to Community Chat, updated popup modal.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/README.md

@@ -128,6 +128,7 @@ your-folder/
 | Out of memory | Set more RAM: `JVM_XMX=4G ./start.sh` |
 | Friends can't connect | Forward port 5520 (TCP+UDP) on your router, or use [playit.gg](https://playit.gg) if you can't port forward |
 
-## Discord
+## Community
 
-Need help? Join the community: https://discord.gg/Fhbb9Yk5WW
+Need help? Join the community: https://chat.sanhost.net/invite/Tfz4jCK4 | TG Channel: https://t.me/hf2p_og | TG Group: https://t.me/sanhostnet
+<!-- Discord: https://discord.gg/Fhbb9Yk5WW -->