car: the nav bar takes the screen's own background everywhere, and the car isn't sent the same cover every second

gearslip/src/main/java/app/seb3thehacker/gearslip/car/CarNavBar.kt

@@ -79,7 +79,6 @@ import app.seb3thehacker.gearslip.car.theme.GsColors
 import app.seb3thehacker.gearslip.car.theme.withTintedSurfaces
 import app.seb3thehacker.gearslip.car.theme.GsIconBox
 import app.seb3thehacker.gearslip.car.theme.GsIconButton
-import app.seb3thehacker.gearslip.car.theme.gsBarShadow
 import app.seb3thehacker.gearslip.car.theme.GsButton
 import app.seb3thehacker.gearslip.car.theme.GsTone
 import app.seb3thehacker.gearslip.car.theme.gsColors
@@ -166,14 +165,11 @@ internal fun CarNavBar(navigator: CarNavigator) {
     val frame by CarEnvironment.frame.collectAsState()
     val running = rememberRunningApps()
 
-    // A full-width strip along the bottom, casting the theme's panel shadow up onto the map so the
+    // A full-width strip along the bottom in the screens' own background, so it reads as part of
-    // bar sits above it rather than beside it. Over the player it's see-through instead, so the
+    // the screen above rather than a panel on it. Over the player it's see-through, so the
-    // player's background and the cover's glow carry on behind it.
+    // cover's glow carries on behind it.
     val overPlayer = navigator.current == CarScreen.Media
-    Surface(
+    Surface(color = if (overPlayer) androidx.compose.ui.graphics.Color.Transparent else MaterialTheme.colorScheme.background) {
-        if (overPlayer) Modifier else Modifier.gsBarShadow(),
-        color = if (overPlayer) androidx.compose.ui.graphics.Color.Transparent else MaterialTheme.colorScheme.surfaceContainer,
-    ) {
         BoxWithConstraints(Modifier.fillMaxWidth().height(NAV_BAR_HEIGHT).padding(horizontal = 10.dp)) {
             Row(Modifier.fillMaxSize(), verticalAlignment = Alignment.CenterVertically) {
                 // Home and Apps are two different places now, not a toggle on one button - the

gearslip/src/main/java/app/seb3thehacker/gearslip/media/CarMediaStatus.kt

@@ -85,7 +85,9 @@ class CarMediaStatus(
     }
 
     private fun sendTrack(now: NowPlaying) {
-        val key = "${now.title}\u0000${now.artist}\u0000${now.album}\u0000${now.durationMs}\u0000${now.art?.generationId}"
+        // Whether there's a cover, not which bitmap: some apps (Metrolist) hand over a fresh copy
+        // of the same cover with every update, and resending it each second wastes the link.
+        val key = "${now.title}\u0000${now.artist}\u0000${now.album}\u0000${now.durationMs}\u0000${now.art != null}"
         if (key == sentTrack) return
         sentTrack = key
         var body = Protobuf.stringField(1, now.title) +