now playing: refresh neighbours when repeat changes

The adjacent artwork effect keys on the item and queue layout, but the predictions now also depend on the repeat mode. Toggling repeat left the cached neighbours stale, so the edge swipe still resisted until the track changed. Key the effect on the repeat mode too, with a route test that toggles repeat and expects the wrapped previous art.

app/src/main/kotlin/com/subtracks/ui/playback/NowPlayingScreen.kt

@@ -244,7 +244,7 @@ fun NowPlayingRoute(
             name = item.title,
         )
     var adjacent by remember { mutableStateOf(AdjacentArt()) }
-    LaunchedEffect(state.item?.id, state.layout) {
+    LaunchedEffect(state.item?.id, state.layout, state.repeat) {
         if (state.item == null) {
             adjacent = AdjacentArt()
             return@LaunchedEffect