Pre-merge audit findings on the connection-scaling perf changes:
- connectionsHeldOpenWithFanout populated firstSeenNs but never read
it — only lastReceiveNs feeds the p50/p99 latency metric. Drop the
unused map and rename the latency map to lastReceiveNs to match
what it actually holds.
- connectionsHeldOpen10k printed/asserted on a variable named rssMb
that was actually JVM heap (`Runtime.totalMemory - freeMemory`).
Rename to heapMb, force a GC + 200 ms settle before reading so the
number reflects retained bytes rather than connect-ramp churn, and
update the assertion message to say "JVM heap" not "heap usage".
Claude
6c792fdf44