fix: live demo static pose & inaccurate sensing data (issue #86)

- Docker default changed from --source simulated to --source auto
  (auto-detects ESP32 on UDP 5005, falls back to simulation)
- Pose derivation now driven by real sensing features: motion_band_power,
  breathing_band_power, variance, dominant_freq_hz, change_points
- Temporal feature extraction: 100-frame circular buffer, Goertzel
  breathing rate estimation (0.1-0.5 Hz), frame-to-frame L2 motion
  detection, SNR-based signal quality metric
- Signal field driven by subcarrier variance spatial mapping instead
  of fixed animation circle
- UI data source indicators: LIVE/RECONNECTING/SIMULATED banner on
  sensing tab, estimation mode badge on live demo tab
- Setup guide panel explaining ESP32 count requirements for each
  capability level (1x: presence, 3x: localization, 4x+: full pose)
- Tick rate improved from 500ms to 100ms (2fps to 10fps)
- Fixed Option<f64> division bug from PR #83
- ADR-035 documents all decisions

Closes #86

Co-Authored-By: claude-flow <ruv@ruv.net>

docker/docker-compose.yml

@@ -12,7 +12,14 @@ services:
       - "5005:5005/udp"  # ESP32 UDP
     environment:
       - RUST_LOG=info
-    command: ["--source", "simulated", "--tick-ms", "100", "--ui-path", "/app/ui", "--http-port", "3000", "--ws-port", "3001"]
+      # CSI_SOURCE controls the data source for the sensing server.
+      # Options: auto (default) — probe for ESP32 UDP then fall back to simulation
+      #          esp32          — receive real CSI frames from an ESP32 on UDP port 5005
+      #          wifi           — use host Wi-Fi RSSI/scan data (Windows netsh)
+      #          simulated      — generate synthetic CSI data (no hardware required)
+      - CSI_SOURCE=${CSI_SOURCE:-auto}
+    # command is passed as arguments to ENTRYPOINT (/bin/sh -c), so $CSI_SOURCE is expanded by the shell.
+    command: ["/app/sensing-server --source ${CSI_SOURCE:-auto} --tick-ms 100 --ui-path /app/ui --http-port 3000 --ws-port 3001"]
 
   python-sensing:
     build: