fix(audio): Linux output device selection and watcher (#176)

* fix(audio): stabilize Linux output device picker and watcher

Keep pinned ALSA/cpal device ids stable when enumeration omits the active
sink or returns an equivalent name. Stop Linux device-watcher from clearing
the pin based on missing list entries; macOS and Windows still treat repeated
absence as unplugged. Settings refresh flow calls canonicalize and refetches
the list; add i18n for the out-of-list device label.

* fix(settings): sort audio output devices by label

cpal enumeration order is arbitrary; order the dropdown by readable label
and place the current OS default device first among concrete outputs.

src/locales/en.ts

@@ -507,6 +507,7 @@ export const enTranslation = {
     audioOutputDeviceRefresh: 'Refresh device list',
     audioOutputDeviceOsDefaultNow: 'current system output',
     audioOutputDeviceListError: 'Could not load the audio device list.',
+    audioOutputDeviceNotInCurrentList: 'not in current list',
     hiResTitle: 'Native Hi-Res Playback',
     hiResEnabled: 'Enable native hi-res playback',
     hiResDesc: "Forces 44.1 kHz output by default for maximum stability. Enable only if your hardware and network reliably support high sample rates (88.2 kHz+).",