feat(library): genre sliders, artist links, and navigation utils

- music landing: diverse per-genre album sliders (online counts /
  offline wide-probe fallback) and home-screen library shortcuts
- add ArtistLinks component and shared navigation/genreDiversity utils
- player/playback-mode refinements across Rust and frontend

src-tauri/android/src/main/java/com/dtourolle/jellytau/player/JellyTauPlayer.kt

@@ -138,6 +138,15 @@ class JellyTauPlayer(private val appContext: Context) {
     /** Current media ID being played */
     private var currentMediaId: String? = null
 
+    /**
+     * Guards against nativeOnPlaybackEnded() firing more than once per loaded
+     * media. ExoPlayer can re-enter STATE_ENDED (e.g. transient buffering near
+     * end of a transcoded stream), which would otherwise notify the backend
+     * twice and, for example, decrement the sleep-timer episode counter twice.
+     * Reset whenever new media is loaded.
+     */
+    private var endedNotified = false
+
     /** Current media metadata for notification updates */
     private var currentTitle: String = ""
     private var currentArtist: String = ""
@@ -208,7 +217,15 @@ class JellyTauPlayer(private val appContext: Context) {
                         // Playback completed
                         android.util.Log.d("JellyTauPlayer", "▶ Playback ended")
                         stopPositionUpdates()
-                        nativeOnPlaybackEnded()
+                        // Only notify the backend once per loaded media. ExoPlayer
+                        // can re-enter STATE_ENDED, which would double-count things
+                        // like the sleep-timer episode counter.
+                        if (!endedNotified) {
+                            endedNotified = true
+                            nativeOnPlaybackEnded()
+                        } else {
+                            android.util.Log.d("JellyTauPlayer", "▶ Playback ended already notified - ignoring")
+                        }
                     }
                     Player.STATE_BUFFERING -> {
                         android.util.Log.d("JellyTauPlayer", "▶ Buffering...")
@@ -322,6 +339,7 @@ class JellyTauPlayer(private val appContext: Context) {
     fun load(url: String, mediaId: String) {
         mainHandler.post {
             currentMediaId = mediaId
+            endedNotified = false
             val mediaItem = MediaItem.fromUri(url)
             exoPlayer.setMediaItem(mediaItem)
             exoPlayer.prepare()
@@ -552,6 +570,7 @@ class JellyTauPlayer(private val appContext: Context) {
     ) {
         mainHandler.post {
             currentMediaId = mediaId
+            endedNotified = false
 
             // Store metadata for notification updates
             currentTitle = title

src-tauri/src/commands/player/mod.rs

@@ -224,6 +224,10 @@ pub struct PlayTracksRequest {
     pub start_index: usize,
     pub shuffle: bool,
     pub context: PlayTracksContext,
+    /// Position (seconds) to resume the starting track from. Used when taking
+    /// over playback from a remote session so we don't restart from 0.
+    #[serde(default)]
+    pub start_position: Option<f64>,
 }
 
 /// Context information for track playback
@@ -1531,7 +1535,7 @@ pub async fn player_play_tracks(
 
     // Play queue
     let controller = player.0.lock().await;
-    controller.play_queue(media_items, request.start_index)
+    controller.play_queue_from(media_items, request.start_index, request.start_position)
         .map_err(|e| e.to_string())?;
 
     // Set queue context

src-tauri/src/lib.rs

@@ -356,6 +356,9 @@ fn specta_builder() -> Builder<tauri::Wry> {
         // Throw on error so generated `commands.*` return Promise<T> and throw,
         // matching the existing frontend's invoke() try/catch convention.
         .error_handling(tauri_specta::ErrorHandlingMode::Throw)
+        .events(tauri_specta::collect_events![
+            crate::player::events::PlayerStatusEvent
+        ])
         .commands(tauri_specta::collect_commands![
             // Player commands
             player_play_item,
@@ -601,11 +604,17 @@ pub fn run() {
     // `.export()` here would try to write `../src/lib/api/bindings.ts` at app
     // startup, which panics on devices (e.g. Android) where that path doesn't exist.
     let builder = specta_builder();
+    let invoke_handler = builder.invoke_handler();
 
     tauri::Builder::default()
         .plugin(tauri_plugin_opener::init())
         .plugin(tauri_plugin_os::init())
-        .setup(|app| {
+        .invoke_handler(invoke_handler)
+        .setup(move |app| {
+            // Mount tauri-specta events so PlayerStatusEvent can be emitted to and
+            // listened for on the frontend via the generated bindings.
+            builder.mount_events(app);
+
             // Initialize database with proper app data directory
             // Check for test mode environment variable first
             let db_path = if let Ok(test_data_dir) = std::env::var("JELLYTAU_DATA_DIR") {
@@ -845,7 +854,6 @@ pub fn run() {
             info!("[INIT] Application setup completed successfully");
             Ok(())
         })
-        .invoke_handler(builder.invoke_handler())
         .run(tauri::generate_context!())
         .expect("error while running tauri application");
 }

src-tauri/src/playback_mode/mod.rs

@@ -20,6 +20,28 @@ pub enum PlaybackMode {
     Idle,
 }
 
+/// Number of Jellyfin ticks per second (100ns units).
+const TICKS_PER_SECOND: f64 = 10_000_000.0;
+
+/// Below this many seconds we treat the position as "at the start" and don't
+/// send a resume position, so a fresh track casts from 0 rather than ~0.
+const RESUME_THRESHOLD_SECONDS: f64 = 0.5;
+
+/// Convert a live playback position (seconds) into the `StartPositionTicks` to
+/// hand to a remote session, or `None` if we're effectively at the start.
+///
+/// Pure helper so the resume-position math is unit-testable without a remote
+/// session or HTTP. The *source* of `position_seconds` matters too: callers
+/// must pass the live backend position (`PlayerController::position()`), not the
+/// snapshot embedded in `PlayerState`, which is stale mid-track on Android.
+fn start_position_ticks_from_seconds(position_seconds: f64) -> Option<i64> {
+    if position_seconds > RESUME_THRESHOLD_SECONDS {
+        Some((position_seconds * TICKS_PER_SECOND) as i64)
+    } else {
+        None
+    }
+}
+
 /// Manages playback mode transfers between local and remote sessions
 pub struct PlaybackModeManager {
     jellyfin_client: Arc<Mutex<Option<JellyfinClient>>>,
@@ -195,7 +217,6 @@ impl PlaybackModeManager {
 
             let queue_arc = player.queue();
             let queue = queue_arc.lock_safe();
-            let state = player.state();
 
             let original_index = queue.current_index().unwrap_or(0);
             let items = queue.items();
@@ -210,7 +231,11 @@ impl PlaybackModeManager {
             }
 
             let (ids, adjusted_index) = self.extract_jellyfin_ids(items, original_index)?;
-            let position = state.position().unwrap_or(0.0);
+            // Read the LIVE backend position, not the snapshot embedded in PlayerState.
+            // On Android the embedded position is only refreshed on play/pause
+            // transitions, so PlayerState::position() is stale (often 0) mid-track;
+            // PlayerController::position() always reflects the backend's current time.
+            let position = player.position();
             let context = queue.context().clone();
 
             log::info!(
@@ -272,12 +297,8 @@ impl PlaybackModeManager {
             }
         };
 
-        // Calculate position in ticks
-        let start_position_ticks = if position_seconds > 0.5 {
-            Some((position_seconds * 10_000_000.0) as i64)
-        } else {
-            None
-        };
+        // Calculate position in ticks (from the live position read above)
+        let start_position_ticks = start_position_ticks_from_seconds(position_seconds);
 
         // Log queue context for debugging (context is tracked but we always send track IDs)
         match &queue_context {
@@ -577,6 +598,23 @@ mod tests {
         );
     }
 
+    /// The resume position handed to a remote session is derived from a live
+    /// playback position. Guards the seconds->ticks conversion and the
+    /// at-the-start threshold (Bug: casting restarted the track from 0).
+    #[test]
+    fn test_start_position_ticks_from_seconds() {
+        // Mid-track positions convert to ticks (10M ticks per second).
+        assert_eq!(start_position_ticks_from_seconds(5.0), Some(50_000_000));
+        assert_eq!(start_position_ticks_from_seconds(123.45), Some(1_234_500_000));
+
+        // At/near the start, send no resume position so the track casts from 0.
+        assert_eq!(start_position_ticks_from_seconds(0.0), None);
+        assert_eq!(start_position_ticks_from_seconds(0.5), None);
+
+        // Just past the threshold resumes rather than restarting.
+        assert!(start_position_ticks_from_seconds(0.6).is_some());
+    }
+
     // Tests for extract_jellyfin_ids - verify all track IDs are sent to remote, not just album/playlist ID
     mod extract_jellyfin_ids_tests {
         use crate::player::{MediaItem, MediaSource, MediaType};

src-tauri/src/player/android/mod.rs

@@ -678,7 +678,12 @@ pub extern "system" fn Java_com_dtourolle_jellytau_player_JellyTauPlayer_nativeO
         // Use tauri::async_runtime::spawn instead of tokio::spawn
         // JNI callbacks happen on arbitrary threads without a Tokio runtime
         tauri::async_runtime::spawn(async move {
-            match controller.lock().await.on_playback_ended().await {
+            // Compute the autoplay decision and release the lock before matching.
+            // Holding the guard across the match would deadlock the AdvanceToNext
+            // arm, which re-locks the controller to call next() — leaving playback
+            // stopped (paused at position 0) instead of advancing.
+            let decision = controller.lock().await.on_playback_ended().await;
+            match decision {
                 Ok(AutoplayDecision::Stop) => {
                     log::debug!("[Autoplay] Decision: Stop playback");
                     // Emit PlaybackEnded event to frontend

src-tauri/src/player/events.rs

@@ -10,7 +10,8 @@ use crate::utils::lock::MutexSafe;
 use log::error;
 use serde::{Deserialize, Serialize};
 use std::sync::Arc;
-use tauri::{AppHandle, Emitter};
+use tauri::AppHandle;
+use tauri_specta::Event;
 
 use super::{MediaSessionType, SleepTimerMode};
 
@@ -20,8 +21,8 @@ use super::{MediaSessionType, SleepTimerMode};
 /// state machine transitions.
 ///
 /// TRACES: UR-005, UR-019, UR-023, UR-026 | DR-001, DR-028, DR-047
-#[derive(Debug, Clone, Serialize, Deserialize)]
-#[serde(tag = "type", rename_all = "snake_case")]
+#[derive(Debug, Clone, Serialize, Deserialize, specta::Type, tauri_specta::Event)]
+#[serde(tag = "type", rename_all = "snake_case", rename_all_fields = "camelCase")]
 pub enum PlayerStatusEvent {
     /// Playback position updated (emitted periodically during playback)
     PositionUpdate {
@@ -113,9 +114,6 @@ pub enum PlayerStatusEvent {
     },
 }
 
-/// Tauri event name for player status events
-pub const PLAYER_EVENT_NAME: &str = "player-event";
-
 /// Trait for emitting player events to the frontend.
 ///
 /// This abstraction allows backends to emit events without depending
@@ -141,7 +139,9 @@ impl TauriEventEmitter {
 
 impl PlayerEventEmitter for TauriEventEmitter {
     fn emit(&self, event: PlayerStatusEvent) {
-        if let Err(e) = self.app_handle.emit(PLAYER_EVENT_NAME, &event) {
+        // Emitted via the tauri-specta Event trait so the payload shape and event
+        // name match the generated TypeScript bindings (events.playerStatusEvent).
+        if let Err(e) = Event::emit(&event, &self.app_handle) {
             error!("Failed to emit player event: {}", e);
         }
     }

src-tauri/src/player/mod.rs

@@ -311,7 +311,27 @@ impl PlayerController {
 
     /// Set the queue and start playing from the specified index
     pub fn play_queue(&self, items: Vec<MediaItem>, start_index: usize) -> Result<(), PlayerError> {
-        debug!("[PlayerController] play_queue: {} items, starting at index {}", items.len(), start_index);
+        self.play_queue_from(items, start_index, None)
+    }
+
+    /// Set the queue and start playing from the specified index, optionally
+    /// resuming the starting track at `start_position` (seconds).
+    ///
+    /// The seek happens immediately after load so the backend never audibly
+    /// starts at 0 and there's no race against a fixed delay. Used when taking
+    /// over playback from a remote session.
+    pub fn play_queue_from(
+        &self,
+        items: Vec<MediaItem>,
+        start_index: usize,
+        start_position: Option<f64>,
+    ) -> Result<(), PlayerError> {
+        debug!(
+            "[PlayerController] play_queue: {} items, starting at index {} (resume: {:?})",
+            items.len(),
+            start_index,
+            start_position
+        );
 
         // Reset autoplay counter on manual queue start
         self.reset_autoplay_count();
@@ -324,6 +344,15 @@ impl PlayerController {
         // Play the current item (without modifying the queue we just set)
         if let Some(item) = self.queue.lock_safe().current().cloned() {
             self.load_and_play(&item)?;
+
+            // Resume from the requested position. Seeking right after load (while
+            // the backend lock is no longer held) avoids the start-at-0-then-jump
+            // race that a delayed frontend seek suffers from.
+            if let Some(position) = start_position {
+                if position > 0.5 {
+                    self.seek(position)?;
+                }
+            }
         }
 
         Ok(())
@@ -1333,6 +1362,44 @@ mod tests {
         }
     }
 
+    /// Resuming a queue at a position seeks the starting track immediately.
+    /// Regression guard for taking over a remote session: the local player must
+    /// pick up where the remote left off, not restart from 0.
+    #[test]
+    fn test_play_queue_from_resumes_at_position() {
+        let controller = PlayerController::default();
+        let items = create_test_items(3);
+
+        controller.play_queue_from(items, 1, Some(42.5)).unwrap();
+
+        {
+            let queue = controller.queue();
+            let queue_lock = queue.lock_safe();
+            assert_eq!(queue_lock.current_index(), Some(1), "Should start at index 1");
+        }
+        assert_eq!(controller.position(), 42.5, "Should resume at the requested position");
+    }
+
+    /// A None / near-zero start position starts the track from the beginning.
+    #[test]
+    fn test_play_queue_from_without_position_starts_at_zero() {
+        let controller = PlayerController::default();
+
+        controller
+            .play_queue_from(create_test_items(2), 0, None)
+            .unwrap();
+        assert_eq!(controller.position(), 0.0, "No resume position starts at 0");
+
+        controller
+            .play_queue_from(create_test_items(2), 0, Some(0.2))
+            .unwrap();
+        assert_eq!(
+            controller.position(),
+            0.0,
+            "Sub-threshold resume position is ignored (starts at 0)"
+        );
+    }
+
     #[test]
     fn test_seek_to_zero() {
         let controller = PlayerController::default();

src-tauri/src/player/state.rs

@@ -61,7 +61,12 @@ pub enum PlayerState {
 }
 
 impl PlayerState {
-    /// Get the current playback position if available
+    /// Get the current playback position if available.
+    ///
+    /// Note: this is the position snapshot embedded in the state at the last
+    /// state transition, not the live backend position. For an up-to-date
+    /// value use `PlayerController::position()`.
+    #[allow(dead_code)]
     pub fn position(&self) -> Option<f64> {
         match self {
             PlayerState::Playing { position, .. } => Some(*position),

src-tauri/src/repository/offline.rs

@@ -864,7 +864,7 @@ impl MediaRepository for OfflineRepository {
 
         let genres = genre_set
             .into_iter()
-            .map(|name| Genre { id: name.clone(), name })
+            .map(|name| Genre { id: name.clone(), name, album_count: None })
             .collect();
 
         Ok(genres)

src-tauri/src/repository/online.rs

@@ -811,7 +811,12 @@ impl MediaRepository for OnlineRepository {
     }
 
     async fn get_genres(&self, parent_id: Option<&str>) -> Result<Vec<Genre>, RepoError> {
-        let mut endpoint = format!("/Genres?UserId={}", self.user_id);
+        // Ask Jellyfin to scope counts to albums and include them, so the
+        // frontend can rank genres by popularity without probing each one.
+        let mut endpoint = format!(
+            "/Genres?UserId={}&IncludeItemTypes=MusicAlbum&Recursive=true&Fields=ItemCounts",
+            self.user_id
+        );
 
         if let Some(pid) = parent_id {
             endpoint.push_str(&format!("&ParentId={}", pid));
@@ -828,17 +833,34 @@ impl MediaRepository for OnlineRepository {
         struct JellyfinGenre {
             id: String,
             name: String,
+            // Which count field Jellyfin populates for a genre under
+            // Fields=ItemCounts varies by server/version: scoped queries may
+            // fill AlbumCount, others only ChildCount. Read whichever is
+            // present so ranking still works. Absent on servers that ignore
+            // Fields=ItemCounts entirely, so all stay optional.
+            album_count: Option<u32>,
+            child_count: Option<u32>,
         }
 
         let response: GenresResponse = self.get_json(&endpoint).await?;
-        Ok(response
+        let genres: Vec<Genre> = response
             .items
             .into_iter()
             .map(|g| Genre {
                 id: g.id,
                 name: g.name,
+                album_count: g.album_count.or(g.child_count),
             })
-            .collect())
+            .collect();
+
+        let with_counts = genres.iter().filter(|g| g.album_count.is_some()).count();
+        log::debug!(
+            "get_genres: {} genres, {} carry counts (AlbumCount/ChildCount)",
+            genres.len(),
+            with_counts
+        );
+
+        Ok(genres)
     }
 
     async fn search(

src-tauri/src/repository/types.rs

@@ -255,6 +255,10 @@ pub struct PlaybackInfo {
 pub struct Genre {
     pub id: String,
     pub name: String,
+    /// Number of albums tagged with this genre, when the backend can supply it
+    /// (online only). Lets the frontend rank/pick genres without probing each
+    /// one. `None` when unknown (e.g. offline).
+    pub album_count: Option<u32>,
 }
 
 /// Image type