Documentation updates: PRD_OAUTH.md (new): - Document OAuth Phase 1 vs Phase 2 approach - Explain why we simplified from DPoP to JWT-only - Detail the new authentication flow - Document known limitations and future work PRD_COMMUNITIES.md: - Mark OAuth authentication as complete (2025-10-16) - Add new critical blocker: subscription indexing - Document missing Jetstream consumer in production - Update security section with completion status PRD_BACKLOG.md: - Mark user subscription auth issue as resolved - Reorganize priorities post-OAuth completion CLAUDE.md: - Update builder guidelines - Clarify security-first principles - Add atProto authentication best practices