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/mobile/src/services/ws.service.ts

@@ -100,13 +100,8 @@ class WsService {
   private buildWsUrl(rawUrl: string): string {
     const parsed = new URL(rawUrl);
     const proto = parsed.protocol === 'https:' || parsed.protocol === 'wss:' ? 'wss:' : 'ws:';
-    // Sensing server runs WS on port 3001 at /ws/sensing
-    // If the HTTP server is on port 3000, connect WS to 3001
-    const wsHost = parsed.port === '3000'
-      ? `${parsed.hostname}:3001`
-      : parsed.host;
-    const wsPath = parsed.port === '3000' ? '/ws/sensing' : WS_PATH;
-    return `${proto}//${wsHost}${wsPath}`;
+    // The /ws/sensing endpoint is served on the same HTTP port (no separate WS port needed).
+    return `${proto}//${parsed.host}/ws/sensing`;
   }
 
   private handleStatusChange(status: ConnectionStatus): void {