🩹(frontend) disable Safari speaker select for LiveKit compatibility

Disable speaker selection on prejoin screen for Safari based on LiveKit
documentation stating audio output selection isn't supported, though
this needs further verification.

Maintains consistency with audio tab behavior until Safari audio output
support can be confirmed. Feature remains available on other browsers
where support is verified.

src/frontend/src/features/rooms/components/Join.tsx

@@ -31,6 +31,7 @@ import { openPermissionsDialog, permissionsStore } from '@/stores/permissions'
 import { ToggleDevice } from './join/ToggleDevice'
 import { SelectDevice } from './join/SelectDevice'
 import { useResolveDefaultDeviceId } from '../livekit/hooks/useResolveDefaultDevice'
+import { isSafari } from '@/utils/livekit'
 
 const onError = (e: Error) => console.error('ERROR', e)
 
@@ -601,17 +602,19 @@ export const Join = ({
                   onSubmit={saveAudioInputDeviceId}
                 />
               </div>
-              <div
-                className={css({
-                  width: '30%',
-                })}
-              >
-                <SelectDevice
-                  kind="audiooutput"
-                  id={audioOutputDeviceId}
-                  onSubmit={saveAudioOutputDeviceId}
-                />
-              </div>
+              {!isSafari() && (
+                <div
+                  className={css({
+                    width: '30%',
+                  })}
+                >
+                  <SelectDevice
+                    kind="audiooutput"
+                    id={audioOutputDeviceId}
+                    onSubmit={saveAudioOutputDeviceId}
+                  />
+                </div>
+              )}
               <div
                 className={css({
                   width: '30%',