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>

src/core/module.ts

@@ -0,0 +1,23 @@
+import type { StateStore } from './state-store.js'
+import type { TelegramClient } from './telegram-client.js'
+import type { TokenManager } from './token-manager.js'
+
+export interface Module {
+  readonly name: string
+  start: () => Promise<void>
+  stop: () => Promise<void>
+  isRunning: () => boolean
+}
+
+export interface ModuleFactory {
+  (config: unknown, deps: ModuleDependencies): Module
+}
+
+export interface ModuleDependencies {
+  telegram: TelegramClient
+  tokenManager?: TokenManager
+  stateStore: StateStore
+  logger: Logger
+}
+
+export type Logger = (module: string, message: string, ...args: unknown[]) => void