feat(desktop): add NIP-46 remote signer (bunker://) login
Support bunker:// URI login for desktop, enabling private key delegation
to remote signers (nsec.app, Amber). Includes heartbeat monitoring,
force-logout on revocation, and ConnectingRelays startup state.
- AccountManager: bunker login/save/load, heartbeat ping, force logout
- LoginCard: auto-detect bunker:// URI, validation, connecting state
- LoginScreen: wire bunker callback, ConnectingRelays screen
- Main.kt: relay timeout, error recovery, scope cleanup, data objects
- ForceLogoutDialog: alert on signer revocation/disconnect
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
nrobi144
6c24c52104