feat(scrobble stats): navigator lower bound, clickable rows, android button to top

- Navigator can't step before logging began: the endpoint returns firstPlayedAt
  (MIN(played_at) over all the user's plays, unfiltered by window); web + android
  disable the back arrow once the shown year/month is at/before that first play.
- Top artists/tracks/albums are now clickable → open the artist / album page (web
  navigates and closes the overlay; android navigates via nav routes). Tracks open
  their album.
- Android: moved the 'Meine Statistiken' button to the top of Settings (was at the
  bottom near logout). SW cache -> ns-v70.

Android compileDebugKotlin + web build green; firstPlayedAt verified server-side.

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

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

@@ -5,6 +5,7 @@ import kotlinx.serialization.Serializable
 // Mirrors the JSON from the scrobble service GET /scrobble/stats.
 @Serializable
 data class ScrobbleStats(
+    val firstPlayedAt: Long? = null,
     val totalPlays: Int = 0,
     val totalSeconds: Long = 0,
     val topArtists: List<StatArtist> = emptyList(),

android/app/src/main/kotlin/com/novasonic/app/ui/AppNavigation.kt

@@ -392,8 +392,10 @@ fun AppNavigation() {
                 }
                 composable("stats") {
                     StatsScreen(
-                        coverUrl = { id -> coverUrl(id) },
-                        onBack   = { navController.popBackStack() },
+                        coverUrl      = { id -> coverUrl(id) },
+                        onBack        = { navController.popBackStack() },
+                        onArtistClick = { id -> navController.navigate("artist/$id") },
+                        onAlbumClick  = { id -> navController.navigate("album/$id") },
                     )
                 }
 

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

@@ -80,6 +80,14 @@ fun SettingsScreen(onOpenStats: () -> Unit = {}) {
             color = NsOnSurface,
         )
 
+        // ── 📊 Statistics (TOP) ──────────────────────────────────────────────
+        OutlinedButton(
+            onClick = onOpenStats,
+            modifier = Modifier.fillMaxWidth().height(48.dp),
+        ) {
+            Text("📊 Meine Statistiken", color = NsOnSurface, fontFamily = Outfit, fontWeight = FontWeight.SemiBold)
+        }
+
         // ── Save button (TOP) ────────────────────────────────────────────────
         SaveButton(vm, state.isSaving, state.savedOk, state.error)
 
@@ -228,15 +236,6 @@ fun SettingsScreen(onOpenStats: () -> Unit = {}) {
 
         HorizontalDivider(modifier = Modifier.padding(vertical = 8.dp), color = NsBorder)
 
-        OutlinedButton(
-            onClick = onOpenStats,
-            modifier = Modifier.fillMaxWidth().height(48.dp),
-        ) {
-            Text("📊 Meine Statistiken", color = NsOnSurface, fontFamily = Outfit, fontWeight = FontWeight.SemiBold)
-        }
-
-        Spacer(Modifier.height(8.dp))
-
         OutlinedButton(
             onClick = { showLogoutDialog = true },
             modifier = Modifier.fillMaxWidth().height(48.dp),

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

@@ -41,6 +41,8 @@ private val MONTHS = listOf(
 fun StatsScreen(
     coverUrl: (String?) -> String?,
     onBack: () -> Unit,
+    onArtistClick: (String) -> Unit = {},
+    onAlbumClick: (String) -> Unit = {},
     vm: StatsViewModel = viewModel(),
 ) {
     val state by vm.state.collectAsStateWithLifecycle()
@@ -82,7 +84,7 @@ fun StatsScreen(
             }
             if (state.view != StatsView.ALL) {
                 Spacer(Modifier.weight(1f))
-                StepArrow("‹", enabled = true) { vm.step(-1) }
+                StepArrow("‹", enabled = !vm.atStart()) { vm.step(-1) }
                 Text(
                     if (state.view == StatsView.YEAR) state.year.toString() else "${MONTHS[state.month]} ${state.year}",
                     fontFamily = Outfit, fontSize = 14.sp, fontWeight = FontWeight.Bold, color = NsOnSurface,
@@ -101,13 +103,18 @@ fun StatsScreen(
             (state.stats?.totalPlays ?: 0) == 0 -> CenterMessage(
                 "Noch keine Wiedergaben in diesem Zeitraum.\nSpiel ein paar Songs — sie erscheinen hier automatisch.",
             )
-            else -> StatsContent(state.stats!!, coverUrl)
+            else -> StatsContent(state.stats!!, coverUrl, onArtistClick, onAlbumClick)
         }
     }
 }
 
 @Composable
-private fun StatsContent(d: ScrobbleStats, coverUrl: (String?) -> String?) {
+private fun StatsContent(
+    d: ScrobbleStats,
+    coverUrl: (String?) -> String?,
+    onArtistClick: (String) -> Unit,
+    onAlbumClick: (String) -> Unit,
+) {
     Column(
         Modifier.fillMaxSize().verticalScroll(rememberScrollState())
             .padding(horizontal = 16.dp).padding(bottom = 24.dp),
@@ -128,7 +135,8 @@ private fun StatsContent(d: ScrobbleStats, coverUrl: (String?) -> String?) {
         if (d.topArtists.isNotEmpty()) {
             SectionHeader("Top-Künstler")
             d.topArtists.forEachIndexed { i, a ->
-                TopRow(i + 1, coverUrl(a.artistId), a.name ?: "—", null, a.plays, circular = true)
+                TopRow(i + 1, coverUrl(a.artistId), a.name ?: "—", null, a.plays, circular = true,
+                    onClick = a.artistId?.let { id -> { onArtistClick(id) } })
             }
             Spacer(Modifier.height(20.dp))
         }
@@ -136,7 +144,8 @@ private fun StatsContent(d: ScrobbleStats, coverUrl: (String?) -> String?) {
         if (d.topTracks.isNotEmpty()) {
             SectionHeader("Top-Songs")
             d.topTracks.forEachIndexed { i, t ->
-                TopRow(i + 1, coverUrl(t.coverArt ?: t.albumId ?: t.songId), t.title ?: "—", t.artist, t.plays)
+                TopRow(i + 1, coverUrl(t.coverArt ?: t.albumId ?: t.songId), t.title ?: "—", t.artist, t.plays,
+                    onClick = t.albumId?.let { id -> { onAlbumClick(id) } })
             }
             Spacer(Modifier.height(20.dp))
         }
@@ -144,7 +153,8 @@ private fun StatsContent(d: ScrobbleStats, coverUrl: (String?) -> String?) {
         if (d.topAlbums.isNotEmpty()) {
             SectionHeader("Top-Alben")
             d.topAlbums.forEachIndexed { i, a ->
-                TopRow(i + 1, coverUrl(a.coverArt ?: a.albumId), a.name ?: "—", a.artist, a.plays)
+                TopRow(i + 1, coverUrl(a.coverArt ?: a.albumId), a.name ?: "—", a.artist, a.plays,
+                    onClick = a.albumId?.let { id -> { onAlbumClick(id) } })
             }
             Spacer(Modifier.height(20.dp))
         }
@@ -193,10 +203,13 @@ private fun SectionHeader(t: String) {
 @Composable
 private fun TopRow(
     rank: Int, cover: String?, title: String, subtitle: String?, plays: Int, circular: Boolean = false,
+    onClick: (() -> Unit)? = null,
 ) {
     Row(
         verticalAlignment = Alignment.CenterVertically,
-        modifier = Modifier.fillMaxWidth().padding(vertical = 5.dp),
+        modifier = Modifier.fillMaxWidth()
+            .then(if (onClick != null) Modifier.clickable(onClick = onClick) else Modifier)
+            .padding(vertical = 5.dp),
     ) {
         Text(
             rank.toString(), fontFamily = Outfit, fontWeight = FontWeight.Bold, fontSize = 13.sp,

android/app/src/main/kotlin/com/novasonic/app/viewmodel/StatsViewModel.kt

@@ -21,6 +21,7 @@ data class StatsUiState(
     val view: StatsView = StatsView.ALL,
     val year: Int = Calendar.getInstance().get(Calendar.YEAR),
     val month: Int = Calendar.getInstance().get(Calendar.MONTH),   // 0-11
+    val firstPlayedAt: Long? = null,   // earliest logged play → navigator lower bound
     val stats: ScrobbleStats? = null,
 )
 
@@ -67,6 +68,20 @@ class StatsViewModel(app: Application) : AndroidViewModel(app) {
         }
     }
 
+    /** True when the shown window is at/before the first logged play — caps stepping backwards. */
+    fun atStart(): Boolean {
+        val s = _state.value
+        val first = s.firstPlayedAt ?: return false
+        val c = Calendar.getInstance().apply { timeInMillis = first * 1000 }
+        val fy = c.get(Calendar.YEAR)
+        val fm = c.get(Calendar.MONTH)
+        return when (s.view) {
+            StatsView.YEAR -> s.year <= fy
+            StatsView.MONTH -> s.year < fy || (s.year == fy && s.month <= fm)
+            else -> false
+        }
+    }
+
     private fun startOf(year: Int, month: Int, day: Int): Long {
         val c = Calendar.getInstance().apply {
             clear()
@@ -99,7 +114,11 @@ class StatsViewModel(app: Application) : AndroidViewModel(app) {
             _state.value = if (stats == null)
                 _state.value.copy(loading = false, error = "Scrobble-Dienst nicht erreichbar")
             else
-                _state.value.copy(loading = false, configured = true, stats = stats)
+                _state.value.copy(
+                    loading = false, configured = true, stats = stats,
+                    // Keep the earliest-play bound once known (a windowed query may return null for it).
+                    firstPlayedAt = stats.firstPlayedAt ?: _state.value.firstPlayedAt,
+                )
         }
     }
 }