YM-OpenClaw

Remove password storage dependency from the convert-to-passkey flow. Instead of the plugin storing and replaying passwords, the user logs in with their own password manager, and the plugin:

1. PageObserver (new) — CDP-based page monitor that auto-attaches to browser pages, detects login page visits, and successful logins via URL transitions
2. Passkey-first guidance — when visiting a login page where a passkey already exists, injects a banner guiding the user to use their passkey
3. Auto passkey registration — after detecting login success, automatically registers a passkey if none exists for that site (opens new tab to security settings)
4. User notification — injects in-page banners when passkeys are created
5. Simplified convert flow — registerPasskeyForSite() replaces convertPasswordToPasskey(), removes all password lookup/login/verification steps

Files changed:
- src/page-observer.ts (new) — PageObserver class
- src/convert-flow.ts — simplified, exports SiteConfig/SITES
- src/tools.ts — updated convert tool description
- src/index.ts — PageObserver lifecycle integration
- src/convert-flow.test.ts — rewritten for new API
- src/page-observer.test.ts (new) — 8 tests