• [API] Remove adaptive congestion control and its public RTT threshold setting. BBRv1 is now the default congestion controller; Cubic remains available when explicitly selected.
• [FIX] BBR: calculate ACK aggregation in bytes, restoring ACK aggregation compensation and upload throughput.
• [FIX] Preserve a zero application close error code (#706).
• [FIX] Check for a stream write reset before pending HTTP/3 headers (#711).
• [FIX] Support multi-tick, multi-packet ClientHellos (#710).
• [API] Permit keepalive PINGs when no streams are open (#699).
• [FIX] Use PROTOCOL_VIOLATION for frames illegal at their encryption level (#697).