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/modules/hytale-launcher/formatter.ts

@@ -0,0 +1,33 @@
+import type { LauncherUpdate } from './tracker.js'
+
+function formatDownloadUrls(downloadUrl: Record<string, Record<string, { url: string, sha256: string }>>): string {
+  const lines: string[] = []
+
+  for (const [os, architectures] of Object.entries(downloadUrl)) {
+    for (const [arch, data] of Object.entries(architectures)) {
+      if (data.url && data.sha256) {
+        lines.push(`  • ${os}/${arch}: <a href="${data.url}">Download</a> (SHA256: <code>${data.sha256.slice(0, 16)}...</code>)`)
+      }
+      else if (data.url) {
+        lines.push(`  • ${os}/${arch}: <a href="${data.url}">Download</a>`)
+      }
+    }
+  }
+
+  return lines.length > 0 ? `\n<b>Downloads:</b>\n${lines.join('\n')}` : ''
+}
+
+export function formatLauncherUpdate(update: LauncherUpdate): string {
+  const { version, previousVersion, downloadUrl } = update
+
+  let message = `<b>🚀 Hytale Launcher Update</b>
+
+<b>New version:</b> <code>${version}</code>
+${previousVersion !== 'unknown' ? `<b>Previous:</b> <code>${previousVersion}</code>` : ''}`
+
+  if (downloadUrl && Object.keys(downloadUrl).length > 0) {
+    message += formatDownloadUrls(downloadUrl)
+  }
+
+  return message
+}

src/modules/hytale-launcher/index.ts

@@ -0,0 +1,73 @@
+import type { Module, ModuleDependencies } from '../../core/module.js'
+import type { HytaleTrackerConfig } from '../../types.js'
+import { formatLauncherUpdate } from './formatter.js'
+import { checkLauncherUpdate } from './tracker.js'
+
+export function hytaleLauncherFactory(
+  moduleConfig: unknown,
+  deps: ModuleDependencies,
+): Module {
+  const config = moduleConfig as HytaleTrackerConfig
+
+  class HytaleLauncherModule implements Module {
+    readonly name = 'hytale-launcher'
+    private dependencies: ModuleDependencies
+    private config: HytaleTrackerConfig
+    private running = false
+    private intervalId: NodeJS.Timeout | null = null
+
+    constructor(cfg: HytaleTrackerConfig, deps: ModuleDependencies) {
+      this.config = cfg
+      this.dependencies = deps
+    }
+
+    isRunning(): boolean {
+      return this.running
+    }
+
+    async start(): Promise<void> {
+      if (this.running)
+        return
+
+      this.dependencies.logger(this.name, `Starting (poll interval: ${this.config.pollIntervalMinutes}min)`)
+
+      // Initial check
+      await this.check()
+
+      // Start polling
+      this.intervalId = setInterval(() => {
+        this.check().catch((err) => {
+          this.dependencies.logger(this.name, `Check failed: ${err}`)
+        })
+      }, this.config.pollIntervalMinutes * 60 * 1000)
+
+      this.running = true
+    }
+
+    async stop(): Promise<void> {
+      if (!this.running)
+        return
+
+      if (this.intervalId) {
+        clearInterval(this.intervalId)
+        this.intervalId = null
+      }
+      this.running = false
+    }
+
+    private async check(): Promise<void> {
+      const update = await checkLauncherUpdate(this.dependencies.stateStore)
+      if (update) {
+        const message = formatLauncherUpdate(update)
+        await this.dependencies.telegram.sendMessage({
+          text: message,
+          chatIds: this.config.chatIds,
+          disableLinkPreview: true,
+        })
+        this.dependencies.logger(this.name, `Update detected: ${update.version}`)
+      }
+    }
+  }
+
+  return new HytaleLauncherModule(config, deps)
+}

src/modules/hytale-launcher/tracker.ts

@@ -0,0 +1,43 @@
+import type { StateStore } from '../../core/state-store.js'
+
+interface LauncherResponse {
+  version: string
+  download_url: Record<string, Record<string, { url: string, sha256: string }>>
+}
+
+export interface LauncherUpdate {
+  version: string
+  previousVersion: string
+  downloadUrl: Record<string, Record<string, { url: string, sha256: string }>>
+}
+
+const ENDPOINT = 'https://launcher.hytale.com/version/release/launcher.json'
+const STATE_KEY = 'hytale-launcher'
+
+export async function checkLauncherUpdate(stateStore: StateStore): Promise<LauncherUpdate | null> {
+  const response = await fetch(ENDPOINT)
+  if (!response.ok) {
+    throw new Error(`Launcher endpoint returned ${response.status}`)
+  }
+
+  const data = await response.json() as LauncherResponse
+  const currentVersion = data.version
+
+  const state = stateStore.get<{ lastVersion?: string, lastCheck?: string }>(STATE_KEY)
+  const lastVersion = state?.lastVersion
+
+  if (lastVersion === currentVersion) {
+    // No update, just update check time
+    stateStore.set(STATE_KEY, { lastVersion: currentVersion, lastCheck: new Date().toISOString() })
+    return null
+  }
+
+  // Update detected
+  stateStore.set(STATE_KEY, { lastVersion: currentVersion, lastCheck: new Date().toISOString() })
+
+  return {
+    version: currentVersion,
+    previousVersion: lastVersion ?? 'unknown',
+    downloadUrl: data.download_url,
+  }
+}