VoiceBlender adds SIP, WebRTC, and WhatsApp call control in Go

VoiceBlender packages SIP, WebRTC, recording, transcription, and agent control behind a single API surface, which makes it easier to build voice workflows without stitching together separate call-handling services. The repo also extends that same control plane to WhatsApp Business Calling and experimental MoQ legs, putting traditional telephony, browser voice, and QUIC-based media into one stack. The next concrete signal to watch is whether the MoQ path moves beyond PoC settings like MOQ_ENABLED=true and draft-11 transport support, or whether usage stays centered on SIP-TLS, WebRTC, and room-based mixing.