Profiler.h: frames, named scopes and phases, recorded on the main thread only (other threads' scopes do nothing). Per second: frames, total and longest frame time, a mergeable frame time histogram (TrafficStats::Histogram) and time per phase. Per report: the packet types that took longest, the worst frames and the frames over a threshold with their heaviest scopes. Profiling sessions merge every frame's scope tree for a while into one (folded stacks for flame graphs). Optional Tracy client (DLU_TRACY, off by default) gets the same frames and scopes. Task 96.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
