refactor: convert to modular system with Hytale update trackers

- Core infrastructure: module interface, Telegram wrapper, OAuth token manager, state store
- Migrate Discord forwarder to modules/discord-forwarder/
- Add Hytale update trackers: launcher, patches, downloader, server
- Support multiple Telegram chats with per-chat topic IDs
- Unified config with legacy migration and env var fallbacks
- Auto-refresh OAuth tokens (5min buffer)

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

.gitignore

@@ -2,7 +2,10 @@
 # Edit at https://www.toptal.com/developers/gitignore?templates=node,visualstudiocode,windows,macos,linux
 
 config.json
+state.json
 .claude
+tokens/*
+!tokens/.gitkeep
 
 ### Linux ###
 *~