🧹 Scheduled screenshot refresh for README

[fusion94]

Description

The README screenshots go stale as the dashboard evolves. Automate periodic screenshot refresh.

Options

• GitHub Actions workflow that runs on push and commits updated screenshots
• Local cron job via OpenClaw/PM2 that runs node scripts/screenshot.js and pushes

Acceptance Criteria

• Screenshots refresh automatically on code changes or on a schedule
• docs/screenshot-*.png always reflects current UI
• No manual step required