Person count was pinned to 1 because the aggregate was derived from
`smoothed_person_score`, an EMA-smoothed *activity* score (amplitude
variance / motion / spectral energy) that saturates near a single
occupant and cannot discriminate count. The count-aware per-node
estimates the ESP32 paths already compute (firmware n_persons, mincut
corr_persons) were stored in NodeState::prev_person_count then discarded
by the aggregator — the same dead-wiring class as #872.
Add `aggregate_person_count(activity_count, node_states)` = max(activity,
node_max) and use it at both ESP32 aggregation sites (edge-vitals + CSI
loop, Some + fallback arms). It can only raise the count when a node
positively reports more occupants, so the lone-occupant case is provably
never inflated (regression-guarded).
5 new unit tests + full suite: 582 passed, 0 failed.
Co-Authored-By: claude-flow <ruv@ruv.net>
a933fc7732