fix(mobile): list desktop and web devices instead of failing the screen

normalizeRegisteredDevice accepted only android/ios, so one desktop row made
the whole Devices screen fail. Accept the server platform list and show the
platform on each card.

apps/mobile-rn/__tests__/devices.test.ts

@@ -27,6 +27,12 @@ describe('device response contract', () => {
     })
   })
 
+  it('accepts desktop and web devices registered to the same account', () => {
+    for (const platform of ['windows', 'macos', 'web', 'ios'] as const) {
+      expect(normalizeRegisteredDevice({ ...row, platform }).platform).toBe(platform)
+    }
+  })
+
   it('rejects missing timestamps and unsupported platforms', () => {
     expect(() => normalizeRegisteredDevice({ ...row, last_seen_at: 'bad' }))
       .toThrow(DeviceServiceError)