Design proposal (not implemented) for three opt-in, serverless additions
layered on the existing capsule/relay/NIP-44 primitives:
- Phone-approval sign-in via a 2-of-2 split credential-capsule key
- Backup codes (each an independent high-entropy recovery path)
- Importing an existing nsec as the everyday identity
Includes a "why not literal TOTP" section and per-feature threat notes.
Co-Authored-By: Claude <[email protected]>
Claude-Session: https://claude.ai/code/session_01GWJbXXhvTx9wo59jSz57J6
