feat(scrobble stats): genre ranking (Top-Genres) — web + android

Play-log now stores each play's genre (from the song tags; web scrobbleLog +
android PlayLogClient capture song.genre). The stats endpoint returns topGenres
(GROUP BY lower(genre), case-insensitive, blanks ignored); web + android render a
Top-Genres section. Schema migrates via ALTER TABLE. Old plays have no genre
(fills going forward, like cover art). SW cache -> ns-v72.

Android compileDebugKotlin + web build green; genre grouping + null-ignore unit-tested.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

android/app/src/main/kotlin/com/novasonic/app/api/model/ScrobbleModels.kt

@@ -11,10 +11,17 @@ data class ScrobbleStats(
     val topArtists: List<StatArtist> = emptyList(),
     val topAlbums: List<StatAlbum> = emptyList(),
     val topTracks: List<StatTrack> = emptyList(),
+    val topGenres: List<StatGenre> = emptyList(),
     val series: List<StatBucket> = emptyList(),
     val byHour: List<StatHour> = emptyList(),
 )
 
+@Serializable
+data class StatGenre(
+    val name: String? = null,
+    val plays: Int = 0,
+)
+
 @Serializable
 data class StatArtist(
     val name: String? = null,

android/app/src/main/kotlin/com/novasonic/app/data/PlayLogClient.kt

@@ -60,6 +60,7 @@ class PlayLogClient(context: Context) {
         val album: String? = null,
         val albumId: String? = null,
         val coverArt: String? = null,
+        val genre: String? = null,
         val duration: Int? = null,
         val playedAt: Long,
         val source: String = "android",
@@ -81,6 +82,7 @@ class PlayLogClient(context: Context) {
             album    = song.album,
             albumId  = song.albumId,
             coverArt = song.coverArt,
+            genre    = song.genre,
             duration = song.duration,
             playedAt = System.currentTimeMillis() / 1000,
         )

android/app/src/main/kotlin/com/novasonic/app/ui/screen/StatsScreen.kt

@@ -159,6 +159,12 @@ private fun StatsContent(
             Spacer(Modifier.height(20.dp))
         }
 
+        if (d.topGenres.isNotEmpty()) {
+            SectionHeader("Top-Genres")
+            d.topGenres.forEachIndexed { i, g -> GenreRow(i + 1, g.name ?: "—", g.plays) }
+            Spacer(Modifier.height(20.dp))
+        }
+
         if (d.byHour.any { it.plays > 0 }) {
             SectionHeader("Hör-Uhr (Stunde)")
             HourClock(d.byHour.map { it.plays })
@@ -166,6 +172,25 @@ private fun StatsContent(
     }
 }
 
+@Composable
+private fun GenreRow(rank: Int, name: String, plays: Int) {
+    Row(
+        verticalAlignment = Alignment.CenterVertically,
+        modifier = Modifier.fillMaxWidth().padding(vertical = 6.dp),
+    ) {
+        Text(
+            rank.toString(), fontFamily = Outfit, fontWeight = FontWeight.Bold, fontSize = 13.sp,
+            color = NsOnSurface2, modifier = Modifier.width(22.dp),
+        )
+        Text(
+            name, fontFamily = Outfit, fontWeight = FontWeight.SemiBold, fontSize = 14.sp,
+            color = NsOnSurface, maxLines = 1, overflow = TextOverflow.Ellipsis,
+            modifier = Modifier.weight(1f).padding(horizontal = 12.dp),
+        )
+        Text("$plays", fontFamily = Outfit, fontWeight = FontWeight.SemiBold, fontSize = 13.sp, color = NsOnSurface2)
+    }
+}
+
 @Composable
 private fun StepArrow(glyph: String, enabled: Boolean, onClick: () -> Unit) {
     Text(