R05A04 2026-03-06 (V.24 Patch)

V.24 Corrects for Call Stability (#117)

* cherrypick changes for V.24 fixes from tsawyer:dvmhost:codex/fix-v24-r05a05-prready;

* finish review and cherrypick changes for FIFO configuration from tsawyer:dvmhost:codex/fix-v24-r05a05-prready;

* based on Tims changes for writeP25Frame() instead of checking if the frame being written is greater than the available space then decrementing the m_p25Space, lets properly decrement the space and do an underflow check, because I am pretty confident that is the real problem here;

* report underflows in debug mode only;

* whoops should be LogDebugEx not LogError;

* fix signedness;