## Features

* UDP packet payloads for ordinary UDP proxies and SUDP now use a dedicated binary codec when frpc and frps successfully negotiate the capability under wire protocol v2, using a more compact wire representation. Wire protocol v1 remains JSON; wire protocol v2 falls back to JSON `UDPPacket` when the peer does not support or did not negotiate the capability.

## Fixes

* Fixed a server panic and remote denial of service caused by a client sending a negative `pool_count`. Negative values are now rejected before work-connection pool resources are allocated.