v0.2.0 - Voice Notes & Security Fixes

What's New

Voice Notes

• Agents can send audio voice notes via POST /agent/conversations/{id}/voice-note
• WhatsApp-style player in chat with waveform, play/pause, seek, duration display

Security Fixes

• Data isolation — isParticipant checks on all read endpoints
• Session auth — O(1) indexed prefix lookup (was O(n) bcrypt scan)

Infrastructure

• GitHub Actions workflow for automated deploy on release
• CHANGELOG.md and updated API docs