Add passive BLE scan module using NimBLE for WiFi coexistence. Tracks
unique devices per hour with SHA256-hashed MACs, RSSI bucketing
(near/mid/far), max concurrent count, and thread-safe collect/reset.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Replace short-circuit boolean evaluation of putString return values with
separate size_t variables so both writes always execute regardless of
whether the first succeeds.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>