Separate WhatsApp auth from daemon into standalone script

- Add src/auth.ts for interactive QR code authentication
- Add `npm run auth` script
- Update setup skill for current Node.js architecture
- Daemon (src/index.ts) now only uses stored credentials

Auth is run during setup; daemon assumes credentials exist and
shows macOS notification if re-auth is needed.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/auth.ts

@@ -0,0 +1,89 @@
+/**
+ * WhatsApp Authentication Script
+ *
+ * Run this during setup to authenticate with WhatsApp.
+ * Displays QR code, waits for scan, saves credentials, then exits.
+ *
+ * Usage: npx tsx src/auth.ts
+ */
+
+import makeWASocket, {
+  useMultiFileAuthState,
+  DisconnectReason,
+  makeCacheableSignalKeyStore,
+} from '@whiskeysockets/baileys';
+import pino from 'pino';
+import qrcode from 'qrcode-terminal';
+import fs from 'fs';
+import path from 'path';
+
+const AUTH_DIR = './store/auth';
+
+const logger = pino({
+  level: 'warn', // Quiet logging - only show errors
+});
+
+async function authenticate(): Promise<void> {
+  fs.mkdirSync(AUTH_DIR, { recursive: true });
+
+  const { state, saveCreds } = await useMultiFileAuthState(AUTH_DIR);
+
+  // Check if already authenticated
+  if (state.creds.registered) {
+    console.log('✓ Already authenticated with WhatsApp');
+    console.log('  To re-authenticate, delete the store/auth folder and run again.');
+    process.exit(0);
+  }
+
+  console.log('Starting WhatsApp authentication...\n');
+
+  const sock = makeWASocket({
+    auth: {
+      creds: state.creds,
+      keys: makeCacheableSignalKeyStore(state.keys, logger),
+    },
+    printQRInTerminal: false,
+    logger,
+    browser: ['NanoClaw', 'Chrome', '1.0.0'],
+  });
+
+  sock.ev.on('connection.update', (update) => {
+    const { connection, lastDisconnect, qr } = update;
+
+    if (qr) {
+      console.log('Scan this QR code with WhatsApp:\n');
+      console.log('  1. Open WhatsApp on your phone');
+      console.log('  2. Tap Settings → Linked Devices → Link a Device');
+      console.log('  3. Point your camera at the QR code below\n');
+      qrcode.generate(qr, { small: true });
+    }
+
+    if (connection === 'close') {
+      const reason = (lastDisconnect?.error as any)?.output?.statusCode;
+
+      if (reason === DisconnectReason.loggedOut) {
+        console.log('\n✗ Logged out. Delete store/auth and try again.');
+        process.exit(1);
+      } else {
+        console.log('\n✗ Connection failed. Please try again.');
+        process.exit(1);
+      }
+    }
+
+    if (connection === 'open') {
+      console.log('\n✓ Successfully authenticated with WhatsApp!');
+      console.log('  Credentials saved to store/auth/');
+      console.log('  You can now start the NanoClaw service.\n');
+
+      // Give it a moment to save credentials, then exit
+      setTimeout(() => process.exit(0), 1000);
+    }
+  });
+
+  sock.ev.on('creds.update', saveCreds);
+}
+
+authenticate().catch((err) => {
+  console.error('Authentication failed:', err.message);
+  process.exit(1);
+});