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/jest.setup.pre.js

@@ -0,0 +1,38 @@
+// Pre-define globals that expo/src/winter/runtime.native.ts would lazily
+// install via require()-with-ESM-import, which jest 30 rejects.
+// By defining them upfront as non-configurable, the `install()` function
+// in installGlobal.ts will skip them with a console.error (which is harmless).
+const globalsToProtect = [
+  'TextDecoder',
+  'TextDecoderStream',
+  'TextEncoderStream',
+  'URL',
+  'URLSearchParams',
+  '__ExpoImportMetaRegistry',
+  'structuredClone',
+];
+
+for (const name of globalsToProtect) {
+  if (globalThis[name] !== undefined) {
+    // Already defined (e.g. Node provides URL, TextDecoder, structuredClone).
+    // Make it non-configurable so expo's install() skips it.
+    try {
+      Object.defineProperty(globalThis, name, {
+        value: globalThis[name],
+        configurable: false,
+        enumerable: true,
+        writable: true,
+      });
+    } catch {
+      // Already non-configurable, fine.
+    }
+  } else {
+    // Not yet defined, set a stub value and make non-configurable.
+    Object.defineProperty(globalThis, name, {
+      value: name === '__ExpoImportMetaRegistry' ? { url: 'http://localhost:8081' } : undefined,
+      configurable: false,
+      enumerable: false,
+      writable: true,
+    });
+  }
+}