Add BufUtilTracker to record per-LBM inflight peak data, wire it
through StatsAccumulator and StatsUpdated message for thread-safe
delivery to the UI. Buffer utilization is displayed in a dedicated
BufUtilScreen accessible via the 'm' keybinding, separate from
the frame stats screen ('d').
Also reject false INIT_DONE frames with version==0 caused by
misaligned data during parser sync, preventing spurious stats resets.
(cherry picked from commit ca920a8e8f)
Co-authored-by: Zhou Xiao <zhouxiao@espressif.com>
4033fceed5