Re-uses the platform/virtual-thread transcripts already committed in
virtual-threads-benchmark rather than re-measuring them, and adds a WebFlux
module measured the same way (client-side java.net.http.HttpClient load
generator against a real Netty server). Covers I/O-bound throughput, a
naive-vs-offloaded CPU-bound comparison that turned up a real, counter-
intuitive fact about this sandbox's default thread-pool sizes
(LoopResources.DEFAULT_IO_WORKER_COUNT=4 vs Schedulers.parallel()'s
availableProcessors()=2), and an event-loop-starvation scenario showing
what the naive endpoint actually costs unrelated /io traffic on the same
server. Companion code for the ankurm.com post "Virtual Threads vs WebFlux
vs Platform Threads: Benchmarks and a Decision Framework." Also fixes the
root README's module table, which was missing the virtual-threads-benchmark
row from an earlier commit.