benches/sim_bench.rs (harness=false, zero deps): fixed-iteration ns/op timing for
hpmcu_tick, cru_poll, modbus_read_holding, rga_improcess, membus_poke_peek. Human
timings to stdout, one JSON trend line per bench to stderr for CI capture. New CI
`bench` job smoke-runs them. Regression-vs-history gating is future work.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017wB8KB3MMQztRDXCMCkPrf
