fix: add error handling and tests for WA Web version fetch

The fetchLatestWaWebVersion call added in #443 could crash the
connection flow if the HTTP fetch fails. Wrap with .catch() to log
and fall back to the default Baileys version.

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

src/channels/whatsapp.ts

@@ -56,7 +56,10 @@ export class WhatsAppChannel implements Channel {
 
     const { state, saveCreds } = await useMultiFileAuthState(authDir);
 
-    const { version } = await fetchLatestWaWebVersion({});
+    const { version } = await fetchLatestWaWebVersion({}).catch((err) => {
+      logger.warn({ err }, 'Failed to fetch latest WA Web version, using default');
+      return { version: undefined };
+    });
     this.sock = makeWASocket({
       version,
       auth: {