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>

ui/mobile/src/hooks/usePoseStream.ts

@@ -1,6 +1,7 @@
 import { useEffect } from 'react';
 import { wsService } from '@/services/ws.service';
 import { usePoseStore } from '@/stores/poseStore';
+import { useSettingsStore } from '@/stores/settingsStore';
 
 export interface UsePoseStreamResult {
   connectionStatus: ReturnType<typeof usePoseStore.getState>['connectionStatus'];
@@ -12,16 +13,20 @@ export function usePoseStream(): UsePoseStreamResult {
   const connectionStatus = usePoseStore((state) => state.connectionStatus);
   const lastFrame = usePoseStore((state) => state.lastFrame);
   const isSimulated = usePoseStore((state) => state.isSimulated);
+  const serverUrl = useSettingsStore((state) => state.serverUrl);
 
   useEffect(() => {
     const unsubscribe = wsService.subscribe((frame) => {
       usePoseStore.getState().handleFrame(frame);
     });
 
+    // Auto-connect to sensing server on mount
+    wsService.connect(serverUrl);
+
     return () => {
       unsubscribe();
     };
-  }, []);
+  }, [serverUrl]);
 
   return { connectionStatus, lastFrame, isSimulated };
 }