Without it, 'Total number of frames seen: 0' in memray stats and flamegraphs
render empty / C-only. Also added --follow-fork so uvicorn workers spawned
as child processes are tracked.
New `profile` optional-deps group, opt-in Pyinstrument ASGI middleware
gated by DECNET_PROFILE_REQUESTS, bench marker + tests/perf/ micro-benchmarks
for repository hot paths, and scripts/profile/ helpers for py-spy/cProfile/memray.
