Add comprehensive Phase 2 documentation: - Complete design document for two-factor domain verification - Implementation guide with code examples - ADR for implementation decisions (ADR-0004) - ADR for rel="me" email discovery (ADR-008) - Phase 1 impact assessment - All 23 clarification questions answered - Updated architecture docs (indieauth-protocol, security) - Updated ADR-005 with rel="me" approach - Updated backlog with technical debt items Design ready for Phase 2 implementation. Generated with Claude Code https://claude.com/claude-code Co-Authored-By: Claude <noreply@anthropic.com>