Marks Sketches A and B done, with a note that A took the simpler
Channel.UNLIMITED + AtomicInteger cap path the original Risks section
called out, sidestepping the channel-swap that the plan first
sketched.
Records that the streaming-filter slice of Sketch C landed in Quartz,
and that the larger envelope-streaming work the plan called out is
unnecessary because MessageDeserializer / CommandDeserializer /
EventDeserializer were already streaming — only the filter sub-object
went through readTree.
Adds the verification benchmarks (connectionsHeldOpen10k,
connectionsHeldOpenWithFanout) to the verification section, with a
correction that what's measured is JVM heap not OS RSS.
Carries forward the not-done items (fan-out de-duplication,
filter-matching index, Netty engine) into the open-work section,
pointing at live-broadcast-fanout-index.md for the highest-leverage
remaining work.
Claude
6f8e7bb520