fix: complete sensing server API, WebSocket connectivity, and mobile tests (#125)

The web UI had persistent 404 errors on model, recording, and training
endpoints, and the sensing WebSocket never connected on Dashboard/Live
Demo tabs because sensingService.start() was only called lazily on
Sensing tab visit.

Server (main.rs):
- Add 14 fully-functional Axum handlers: model CRUD (7), recording
  lifecycle (4), training control (3)
- Scan data/models/ and data/recordings/ at startup
- Recording writes CSI frames to .jsonl via tokio background task
- Model load/unload lifecycle with state tracking

Web UI (app.js):
- Import and start sensingService early in initializeServices() so
  Dashboard and Live Demo tabs connect to /ws/sensing immediately

Mobile (ws.service.ts):
- Fix WebSocket URL builder to use same-origin port instead of
  hardcoded port 3001

Mobile (jest.config.js):
- Fix testPathIgnorePatterns that was ignoring the entire test directory

Mobile (25 test files):
- Replace all it.todo() placeholder tests with real implementations
  covering components, services, stores, hooks, screens, and utils

ADR-043 documents all changes.

ui/services/sensing.service.js

@@ -9,8 +9,8 @@
  * emit simulated frames so the UI can clearly distinguish live vs. fallback data.
  */
 
-// Derive WebSocket URL from the page origin so it works on any port
-// (Docker :3000, native :8080, etc.)
+// Derive WebSocket URL from the page origin so it works on any port.
+// The /ws/sensing endpoint is available on the same HTTP port (3000).
 const _wsProto = (typeof window !== 'undefined' && window.location.protocol === 'https:') ? 'wss:' : 'ws:';
 const _wsHost  = (typeof window !== 'undefined' && window.location.host) ? window.location.host : 'localhost:3000';
 const SENSING_WS_URL = `${_wsProto}//${_wsHost}/ws/sensing`;