Documents the concrete 4-layer development sequence for closing the
hardware gap: firmware (ESP-IDF C), UDP aggregator (Rust), CsiFrame→CsiData
bridge, and Python _read_raw_data() UDP socket replacement. Builds on
ADR-012 architecture and existing wifi-densepose-hardware parser crate.
Includes testability path for all layers before hardware acquisition.
https://claude.ai/code/session_01BSBAQJ34SLkiJy4A8SoiL4
