feat: add periodic version check with soft reconnection

Implements automatic version updates that are transparent to users:

- Checks for new WhatsApp Web version every 6 hours (configurable)
- When new version detected, saves it for next natural reconnection
- Emits 'version.update' event so users can track updates
- No disconnection required - WhatsApp naturally reconnects every 30min-2h
- Cleans up interval when socket closes

Configuration:
```typescript
const sock = await makeWASocketAutoVersion({
    auth: state,
    versionCheckIntervalMs: 6 * 60 * 60 * 1000 // 6 hours (default)
})

sock.ev.on('version.update', ({ currentVersion, newVersion, isCritical }) => {
    console.log(`New version: ${newVersion.join('.')}`)
})
```

src/Defaults/index.ts

@@ -47,9 +47,13 @@ export const PROCESSABLE_HISTORY_TYPES = [
 	proto.HistorySync.HistorySyncType.INITIAL_STATUS_V3
 ]
 
+// 6 hours in milliseconds
+const SIX_HOURS_MS = 6 * 60 * 60 * 1000
+
 export const DEFAULT_CONNECTION_CONFIG: SocketConfig = {
 	version: version as WAVersion,
 	fetchLatestVersion: false,
+	versionCheckIntervalMs: SIX_HOURS_MS,
 	browser: Browsers.macOS('Chrome'),
 	waWebSocketUrl: 'wss://web.whatsapp.com/ws/chat',
 	connectTimeoutMs: 20_000,