feat(slint): offline manager 1:1 — covers, artist rail, sort, failed-only, persisted limit

Closes the v1 gaps in the offline manager toward Tauri parity:

- Album COVERS: rows load the on-disk cover.jpg (per album). Built Send-safely
  — the worker passes the cover PATH (string), the image is decoded on the UI
  thread (slint::Image is not Send).
- Two-pane layout with an A-Z ARTIST RAIL (left, "All artists" + per-artist
  "N albums · M tracks", selectable) + the discography list (right).
- SORT dropdown (A-Z / Recent / Largest / Smallest; Recent uses the DB's
  last_accessed_at DESC order) and a "Failed only" toggle. Filter state lives
  Rust-side (offline_manager) so rebuild can read it off-thread; mirrored back
  onto OfflineManagerState for the UI.
- Limit now PERSISTS to disk (<audio>/offline_limit), restored on activate via
  apply_persisted_limit; the manager's edit-limit writes it.
- Manager mutations (remove/redownload/clear) now rebuild on completion
  (offline_manager::rebuild made pub, called at the end of each cache op) —
  the 500ms timed reload hack is gone.

Deferred (user-accepted): the "track no longer available on Qobuz" case —
offline copy still plays, but warn it can't be re-downloaded / won't work on
Qobuz Connect.

qbz-slint compiles clean.

cc

crates/qbz-slint/src/main.rs

@@ -3286,6 +3286,33 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             offline_manager::load(weak.clone(), handle.clone());
         });
     }
+    {
+        let weak = window.as_weak();
+        let handle = handle.clone();
+        window
+            .global::<OfflineManagerActions>()
+            .on_select_artist(move |name| {
+                offline_manager::select_artist(weak.clone(), handle.clone(), name.to_string());
+            });
+    }
+    {
+        let weak = window.as_weak();
+        let handle = handle.clone();
+        window
+            .global::<OfflineManagerActions>()
+            .on_set_sort(move |i| {
+                offline_manager::set_sort(weak.clone(), handle.clone(), i);
+            });
+    }
+    {
+        let weak = window.as_weak();
+        let handle = handle.clone();
+        window
+            .global::<OfflineManagerActions>()
+            .on_toggle_failed(move || {
+                offline_manager::toggle_failed(weak.clone(), handle.clone());
+            });
+    }
     {
         let weak = window.as_weak();
         let runtime = runtime.clone();
@@ -3295,7 +3322,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             .on_remove_track(move |id| {
                 if let Ok(tid) = id.parse::<u64>() {
                     offline_cache::remove_cached(runtime.clone(), weak.clone(), handle.clone(), tid);
-                    offline_manager::reload_soon(weak.clone(), handle.clone());
                 }
             });
     }
@@ -3306,7 +3332,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
             .global::<OfflineManagerActions>()
             .on_remove_album(move |aid| {
                 offline_cache::remove_album(weak.clone(), handle.clone(), aid.to_string());
-                offline_manager::reload_soon(weak.clone(), handle.clone());
             });
     }
     {
@@ -3323,7 +3348,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                         handle.clone(),
                         tid,
                     );
-                    offline_manager::reload_soon(weak.clone(), handle.clone());
                 }
             });
     }
@@ -3341,7 +3365,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                     aid.to_string(),
                     false,
                 );
-                offline_manager::reload_soon(weak.clone(), handle.clone());
             });
     }
     {
@@ -3358,7 +3381,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                     aid.to_string(),
                     true,
                 );
-                offline_manager::reload_soon(weak.clone(), handle.clone());
             });
     }
     {
@@ -3375,7 +3397,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         let handle = handle.clone();
         window.global::<OfflineManagerActions>().on_clear_all(move || {
             offline_cache::clear_all(weak.clone(), handle.clone());
-            offline_manager::reload_soon(weak.clone(), handle.clone());
         });
     }
     {

crates/qbz-slint/src/offline.rs

@@ -58,6 +58,11 @@ pub async fn activate(user_id: u64) {
         log::error!("[qbz-slint] offline: init_at failed: {e}");
         return;
     }
+    // Restore the persisted cache size limit (written by the manager's
+    // edit-limit). Falls back to the 5 GB default when absent.
+    if let Some(bytes) = read_persisted_limit(&state.get_cache_path()) {
+        state.apply_persisted_limit(Some(bytes)).await;
+    }
     if let Err(e) = state.init_library_connection(&data_dir).await {
         // Non-fatal: cached playback still resolves from index.db; only the
         // library-row sync (show-in-library) needs this connection.
@@ -68,6 +73,28 @@ pub async fn activate(user_id: u64) {
     log::info!("[qbz-slint] offline cache activated for user {user_id}");
 }
 
+/// The on-disk limit file (next to index.db, in the per-user audio dir).
+fn limit_file(audio_dir: &str) -> std::path::PathBuf {
+    std::path::Path::new(audio_dir).join("offline_limit")
+}
+
+fn read_persisted_limit(audio_dir: &str) -> Option<u64> {
+    std::fs::read_to_string(limit_file(audio_dir))
+        .ok()
+        .and_then(|s| s.trim().parse::<u64>().ok())
+}
+
+/// Persist the cache size limit (bytes) to disk for the active cache, so the
+/// manager's edit-limit survives restarts.
+pub async fn persist_limit(bytes: u64) {
+    if let Some(off) = get().await {
+        let path = limit_file(&off.get_cache_path());
+        if let Err(e) = std::fs::write(&path, bytes.to_string()) {
+            log::warn!("[qbz-slint] offline: persist limit failed: {e}");
+        }
+    }
+}
+
 /// Tear down the offline cache on logout.
 pub async fn deactivate() {
     if let Some(state) = slot().lock().await.take() {

crates/qbz-slint/src/offline_cache.rs

@@ -379,6 +379,7 @@ pub fn remove_album(
             }
         });
         crate::toast::success_weak(&weak, "Removed album from offline");
+        crate::offline_manager::rebuild(weak.clone()).await;
     });
 }
 
@@ -419,6 +420,7 @@ pub fn redownload_track(
             row_sink(weak.clone()),
             off.cache_semaphore.clone(),
         );
+        crate::offline_manager::rebuild(weak.clone()).await;
     });
 }
 
@@ -468,6 +470,7 @@ pub fn redownload_album(
                 off.cache_semaphore.clone(),
             );
         }
+        crate::offline_manager::rebuild(weak.clone()).await;
     });
 }
 
@@ -504,6 +507,7 @@ pub fn clear_all(weak: slint::Weak<AppWindow>, handle: tokio::runtime::Handle) {
             s.clear();
         }
         crate::toast::success_weak(&weak, "Offline cache cleared");
+        crate::offline_manager::rebuild(weak.clone()).await;
     });
 }
 
@@ -551,5 +555,6 @@ pub fn remove_cached(
         mark_cached(id, false);
         push_status(&weak, id, 0, 0.0);
         crate::toast::success_weak(&weak, "Removed from offline");
+        crate::offline_manager::rebuild(weak.clone()).await;
     });
 }

crates/qbz-slint/src/offline_manager.rs

@@ -1,16 +1,53 @@
-//! Offline Cache Manager controller — loads the cached-tracks rollup + stats
+//! Offline Cache Manager controller — loads the artist→album→track rollup +
-//! into `OfflineManagerState`. Per-item actions reuse `offline_cache::*`
+//! stats into `OfflineManagerState`. Per-item actions reuse `offline_cache::*`
-//! (Slice 3); this module owns the data load + the size-limit edit.
+//! (Slice 3); this module owns the data load, the toolbar filters (artist
+//! rail / sort / show-only-failed), the album covers, and the size-limit edit.
 
 use std::collections::BTreeMap;
+use std::sync::{Mutex as StdMutex, OnceLock};
 
 use qbz_offline_cache::{CachedTrackInfo, OfflineCacheStatus};
 use slint::{ComponentHandle, ModelRc, SharedString, VecModel};
 
-use crate::{AppWindow, OfflineManagerState, OfflineRow};
+use crate::{AppWindow, OfflineArtist, OfflineManagerState, OfflineRow};
 
 const GB: u64 = 1024 * 1024 * 1024;
 
+// --- Toolbar filter state (Rust-side source of truth) -------------------
+// The rebuild runs on a tokio task and can't read Slint props cross-thread,
+// so the artist selection / sort / show-only-failed live here. The UI
+// actions update these + trigger a rebuild; the rebuild mirrors them back
+// onto OfflineManagerState for the dropdown / toggle / rail display.
+
+#[derive(Clone)]
+struct Filters {
+    selected_artist: String, // "" = all
+    sort: i32,               // 0 alpha / 1 recent / 2 largest / 3 smallest
+    show_only_failed: bool,
+}
+
+impl Default for Filters {
+    fn default() -> Self {
+        Self {
+            selected_artist: String::new(),
+            sort: 0,
+            show_only_failed: false,
+        }
+    }
+}
+
+static FILTERS: OnceLock<StdMutex<Filters>> = OnceLock::new();
+
+fn filters() -> &'static StdMutex<Filters> {
+    FILTERS.get_or_init(|| StdMutex::new(Filters::default()))
+}
+
+fn current_filters() -> Filters {
+    filters().lock().map(|f| f.clone()).unwrap_or_default()
+}
+
+// --- Formatting ---------------------------------------------------------
+
 fn human_size(bytes: u64) -> String {
     let b = bytes as f64;
     if bytes >= GB {
@@ -28,7 +65,7 @@ fn track_status_int(s: &OfflineCacheStatus) -> i32 {
     match s {
         OfflineCacheStatus::Ready => 3,
         OfflineCacheStatus::Failed => 4,
-        _ => 2, // queued / downloading
+        _ => 2,
     }
 }
 
@@ -36,48 +73,128 @@ fn fmt_duration(secs: u64) -> String {
     format!("{}:{:02}", secs / 60, secs % 60)
 }
 
-/// Read the index.db, build the album→track rollup + stats, and push them to
+fn album_size(group: &[CachedTrackInfo]) -> u64 {
-/// `OfflineManagerState`.
+    group.iter().map(|t| t.file_size_bytes).sum()
-async fn rebuild(weak: slint::Weak<AppWindow>) {
+}
+
+/// Path of an album's on-disk `cover.jpg` (next to one track's CMAF bundle),
+/// or "" when it doesn't exist. Computed on the worker (a `String` is `Send`);
+/// the image itself is loaded on the UI thread (`slint::Image` is NOT `Send`).
+fn cover_path(cache_path: &str, track_id: u64) -> String {
+    let p = std::path::Path::new(cache_path)
+        .join("tracks-cmaf")
+        .join(track_id.to_string())
+        .join("cover.jpg");
+    if p.exists() {
+        p.to_string_lossy().to_string()
+    } else {
+        String::new()
+    }
+}
+
+/// Load a cover image from a path on the UI thread (empty path / missing -> default).
+fn load_cover(path: &str) -> slint::Image {
+    if path.is_empty() {
+        return slint::Image::default();
+    }
+    slint::Image::load_from_path(std::path::Path::new(path)).unwrap_or_default()
+}
+
+/// Worker-built, `Send` row data. Converted to the (non-`Send`) `OfflineRow`
+/// on the UI thread, where the cover image is decoded.
+struct RowData {
+    kind: &'static str,
+    album_id: String,
+    track_id: String,
+    title: String,
+    subtitle: String,
+    meta: String,
+    status: i32,
+    progress: f32,
+    cover_path: String,
+}
+
+// --- Data load ----------------------------------------------------------
+
+/// Read the index.db, build the artist→album→track rollup + stats (applying
+/// the current toolbar filters), and push them to `OfflineManagerState`.
+/// `pub` so the cache mutation fns refresh the manager after their DB op.
+pub async fn rebuild(weak: slint::Weak<AppWindow>) {
+    let f = current_filters();
     let off = crate::offline::get().await;
-    let (tracks, limit): (Vec<CachedTrackInfo>, Option<u64>) = match off {
+    let (tracks, limit, cache_path): (Vec<CachedTrackInfo>, Option<u64>, String) = match off {
         Some(ref o) => {
             let limit = *o.limit_bytes.lock().await;
+            let cp = o.get_cache_path();
             let guard = o.db.lock().await;
             let tracks = guard
                 .as_ref()
                 .and_then(|db| db.get_all_tracks().ok())
                 .unwrap_or_default();
-            (tracks, limit)
+            (tracks, limit, cp)
         }
-        None => (Vec::new(), None),
+        None => (Vec::new(), None, String::new()),
     };
 
     let total_size: u64 = tracks.iter().map(|t| t.file_size_bytes).sum();
     let tracks_count = tracks.len() as i32;
 
-    // Group by album_id, remembering first-seen order.
+    // album_id -> (artist, album_title, tracks), first-seen order (the DB
-    let mut order: Vec<String> = Vec::new();
+    // already returns rows most-recently-accessed first, so this order is
-    let mut groups: BTreeMap<String, (String, String, Vec<CachedTrackInfo>)> = BTreeMap::new();
+    // the "recent" sort).
+    let mut album_order: Vec<String> = Vec::new();
+    let mut albums: BTreeMap<String, (String, String, Vec<CachedTrackInfo>)> = BTreeMap::new();
     for t in tracks {
         let aid = t.album_id.clone().unwrap_or_else(|| "__singles__".to_string());
-        if !groups.contains_key(&aid) {
+        if !albums.contains_key(&aid) {
-            order.push(aid.clone());
+            album_order.push(aid.clone());
         }
-        let album = t.album.clone().unwrap_or_else(|| "Singles".to_string());
+        let title = t.album.clone().unwrap_or_else(|| "Singles".to_string());
-        groups
+        albums
             .entry(aid)
-            .or_insert_with(|| (album, t.artist.clone(), Vec::new()))
+            .or_insert_with(|| (t.artist.clone(), title, Vec::new()))
             .2
             .push(t);
     }
 
-    let mut rows: Vec<OfflineRow> = Vec::new();
+    // Artist rail: name -> (album_count, track_count), A-Z (BTreeMap order).
+    let mut artist_stats: BTreeMap<String, (usize, usize)> = BTreeMap::new();
+    for aid in &album_order {
+        let (artist, _title, group) = &albums[aid];
+        let e = artist_stats.entry(artist.clone()).or_insert((0, 0));
+        e.0 += 1;
+        e.1 += group.len();
+    }
+    let artists: Vec<OfflineArtist> = artist_stats
+        .iter()
+        .map(|(name, (albums_n, tracks_n))| OfflineArtist {
+            name: name.clone().into(),
+            meta: format!("{} albums · {} tracks", albums_n, tracks_n).into(),
+            selected: *name == f.selected_artist,
+        })
+        .collect();
+
+    // Album display order per the sort.
+    let mut order = album_order.clone();
+    match f.sort {
+        0 => order.sort_by(|a, b| albums[a].1.to_lowercase().cmp(&albums[b].1.to_lowercase())),
+        2 => order.sort_by(|a, b| album_size(&albums[b].2).cmp(&album_size(&albums[a].2))),
+        3 => order.sort_by(|a, b| album_size(&albums[a].2).cmp(&album_size(&albums[b].2))),
+        _ => {} // 1 recent — keep the DB's last_accessed_at DESC order
+    }
+
+    let mut rows: Vec<RowData> = Vec::new();
     for aid in &order {
-        let (album, artist, group) = groups.get(aid).unwrap();
+        let (artist, title, group) = &albums[aid];
+        if !f.selected_artist.is_empty() && *artist != f.selected_artist {
+            continue;
+        }
         let any_failed = group
             .iter()
             .any(|t| matches!(t.status, OfflineCacheStatus::Failed));
+        if f.show_only_failed && !any_failed {
+            continue;
+        }
         let any_active = group.iter().any(|t| {
             matches!(
                 t.status,
@@ -96,27 +213,35 @@ async fn rebuild(weak: slint::Weak<AppWindow>) {
         } else {
             0
         };
-        let album_size: u64 = group.iter().map(|t| t.file_size_bytes).sum();
+        let cover_path = group
-        rows.push(OfflineRow {
+            .first()
-            kind: "album".into(),
+            .map(|t| cover_path(&cache_path, t.track_id))
-            album_id: aid.clone().into(),
+            .unwrap_or_default();
-            track_id: SharedString::new(),
+        rows.push(RowData {
-            title: album.clone().into(),
+            kind: "album",
-            subtitle: artist.clone().into(),
+            album_id: aid.clone(),
-            meta: format!("{} tracks · {}", group.len(), human_size(album_size)).into(),
+            track_id: String::new(),
+            title: title.clone(),
+            subtitle: artist.clone(),
+            meta: format!("{} tracks · {}", group.len(), human_size(album_size(group))),
             status: album_status,
             progress: 0.0,
+            cover_path,
         });
         for t in group {
-            rows.push(OfflineRow {
+            if f.show_only_failed && !matches!(t.status, OfflineCacheStatus::Failed) {
-                kind: "track".into(),
+                continue;
-                album_id: aid.clone().into(),
+            }
-                track_id: t.track_id.to_string().into(),
+            rows.push(RowData {
-                title: t.title.clone().into(),
+                kind: "track",
-                subtitle: t.artist.clone().into(),
+                album_id: aid.clone(),
-                meta: fmt_duration(t.duration_secs).into(),
+                track_id: t.track_id.to_string(),
+                title: t.title.clone(),
+                subtitle: t.artist.clone(),
+                meta: fmt_duration(t.duration_secs),
                 status: track_status_int(&t.status),
                 progress: t.progress_percent as f32 / 100.0,
+                cover_path: String::new(),
             });
         }
     }
@@ -133,12 +258,32 @@ async fn rebuild(weak: slint::Weak<AppWindow>) {
 
     let _ = weak.upgrade_in_event_loop(move |w| {
         let st = w.global::<OfflineManagerState>();
-        st.set_rows(ModelRc::new(VecModel::from(rows)));
+        // Build OfflineRow on the UI thread (decodes the cover images here —
+        // slint::Image is not Send, so it can't be built on the worker).
+        let offline_rows: Vec<OfflineRow> = rows
+            .into_iter()
+            .map(|rd| OfflineRow {
+                kind: rd.kind.into(),
+                album_id: rd.album_id.into(),
+                track_id: rd.track_id.into(),
+                title: rd.title.into(),
+                subtitle: rd.subtitle.into(),
+                meta: rd.meta.into(),
+                status: rd.status,
+                progress: rd.progress,
+                cover: load_cover(&rd.cover_path),
+            })
+            .collect();
+        st.set_rows(ModelRc::new(VecModel::from(offline_rows)));
+        st.set_artists(ModelRc::new(VecModel::from(artists)));
         st.set_tracks_count(tracks_count);
         st.set_size_text(SharedString::from(size_text));
         st.set_limit_text(SharedString::from(limit_text));
         st.set_usage(usage);
         st.set_limit_gb(limit_gb);
+        st.set_selected_artist(SharedString::from(f.selected_artist));
+        st.set_sort_index(f.sort);
+        st.set_show_only_failed(f.show_only_failed);
         st.set_loading(false);
     });
 }
@@ -151,22 +296,37 @@ pub fn load(weak: slint::Weak<AppWindow>, handle: tokio::runtime::Handle) {
     handle.spawn(rebuild(weak));
 }
 
-/// Rebuild after a brief delay — used after a manager mutation (remove /
+// --- Toolbar actions ----------------------------------------------------
-/// re-download) so the list reflects the async DB op without a manual refresh.
+
-pub fn reload_soon(weak: slint::Weak<AppWindow>, handle: tokio::runtime::Handle) {
+pub fn select_artist(weak: slint::Weak<AppWindow>, handle: tokio::runtime::Handle, name: String) {
-    handle.spawn(async move {
+    if let Ok(mut f) = filters().lock() {
-        tokio::time::sleep(std::time::Duration::from_millis(500)).await;
+        f.selected_artist = name;
-        rebuild(weak).await;
+    }
-    });
+    handle.spawn(rebuild(weak));
 }
 
-/// Set the in-memory cache size limit (GB) and refresh. (Session-scoped for
+pub fn set_sort(weak: slint::Weak<AppWindow>, handle: tokio::runtime::Handle, index: i32) {
-/// now — Slint-side persistence is a follow-up.)
+    if let Ok(mut f) = filters().lock() {
+        f.sort = index;
+    }
+    handle.spawn(rebuild(weak));
+}
+
+pub fn toggle_failed(weak: slint::Weak<AppWindow>, handle: tokio::runtime::Handle) {
+    if let Ok(mut f) = filters().lock() {
+        f.show_only_failed = !f.show_only_failed;
+    }
+    handle.spawn(rebuild(weak));
+}
+
+/// Set the cache size limit (GB), persist it to disk, and refresh.
 pub fn set_limit(weak: slint::Weak<AppWindow>, handle: tokio::runtime::Handle, gb: i32) {
     handle.spawn(async move {
+        let bytes = (gb.max(1) as u64) * GB;
         if let Some(off) = crate::offline::get().await {
-            *off.limit_bytes.lock().await = Some((gb.max(1) as u64) * GB);
+            *off.limit_bytes.lock().await = Some(bytes);
         }
+        crate::offline::persist_limit(bytes).await;
         rebuild(weak).await;
     });
 }

crates/qbz-slint/ui/offline/OfflineManagerView.slint

@@ -1,17 +1,20 @@
 // Offline Cache Manager — the standalone manage-downloads surface (Tauri's
-// OfflineCacheManagerView). Fixed header (Back + title) + a stats bar (totals
+// OfflineCacheManagerView). Header (Back + title) + a stats bar (totals /
-// / usage bar / edit-limit / open-folder / clear-all) over a scrolling list
+// usage bar / edit-limit / open-folder / clear-all) + a toolbar (sort
-// of album-header + track rows (per-row remove / re-download).
+// dropdown / show-only-failed) over a two-pane body: a left A-Z artist rail
+// and a right scrolling list of album-header (with cover) + track rows
+// (per-row remove / re-download).
 //
-// Rows are precomputed in Rust (crate::offline_manager) and pushed as a flat
+// Rows + artists are precomputed in Rust (crate::offline_manager) and pushed
-// [OfflineRow] model; actions go through OfflineManagerActions.
+// as models; actions go through OfflineManagerActions.
 
 import { ScrollView } from "std-widgets.slint";
 import { Theme } from "../foundation/semantic-colors.slint";
 import { Typography } from "../foundation/typography.slint";
 import { Radius } from "../foundation/radius.slint";
-import { OfflineManagerState, OfflineManagerActions, OfflineRow } from "../state.slint";
+import { OfflineManagerState, OfflineManagerActions, OfflineRow, OfflineArtist } from "../state.slint";
 import { QbzIcon } from "../primitives/QbzIcon.slint";
+import { QbzSelect } from "../primitives/QbzSelect.slint";
 import { LoadingSpinner } from "../primitives/LoadingSpinner.slint";
 import { NavButtons } from "../shell/NavButtons.slint";
 
@@ -40,8 +43,7 @@ component IconBtn inherits Rectangle {
     }
 }
 
-// The cache-status glyph: 2 downloading (spinning loader) / 3 ready (check) /
+// The cache-status glyph (downloading spins).
-// 4 failed (alert) / else cloud.
 component StatusIcon inherits Rectangle {
     in property <int> status;
     width: 18px;
@@ -69,14 +71,52 @@ component StatusIcon inherits Rectangle {
     }
 }
 
+// One artist-rail row.
+component ArtistRailRow inherits Rectangle {
+    in property <string> name;
+    in property <string> meta;
+    in property <bool> active;
+    callback clicked;
+    height: 48px;
+    border-radius: 8px;
+    background: root.active ? Theme.surface-elevated : (ta.has-hover ? #ffffff10 : transparent);
+    HorizontalLayout {
+        padding-left: 12px;
+        padding-right: 8px;
+        VerticalLayout {
+            alignment: center;
+            spacing: 2px;
+            Text {
+                text: root.name;
+                color: root.active ? Theme.accent : Theme.text-primary;
+                font-size: Typography.legal;
+                font-weight: root.active ? Typography.semibold : Typography.regular;
+                overflow: elide;
+            }
+            Text {
+                text: root.meta;
+                color: Theme.text-muted;
+                font-size: 11px;
+                overflow: elide;
+            }
+        }
+    }
+    ta := TouchArea {
+        mouse-cursor: pointer;
+        clicked => {
+            root.clicked();
+        }
+    }
+}
+
 export component OfflineManagerView inherits Rectangle {
     background: Theme.surface-main;
 
     VerticalLayout {
         padding: 24px;
-        spacing: 16px;
+        spacing: 14px;
 
-        // Header — back + title.
+        // Header.
         HorizontalLayout {
             vertical-stretch: 0;
             spacing: 12px;
@@ -101,7 +141,6 @@ export component OfflineManagerView inherits Rectangle {
             HorizontalLayout {
                 padding: 16px;
                 spacing: 20px;
-                // Totals.
                 VerticalLayout {
                     alignment: center;
                     Text {
@@ -116,7 +155,6 @@ export component OfflineManagerView inherits Rectangle {
                         font-size: Typography.legal;
                     }
                 }
-                // Usage bar.
                 Rectangle {
                     horizontal-stretch: 1;
                     VerticalLayout {
@@ -136,7 +174,6 @@ export component OfflineManagerView inherits Rectangle {
                         }
                     }
                 }
-                // Edit limit (GB).
                 VerticalLayout {
                     alignment: center;
                     HorizontalLayout {
@@ -178,7 +215,6 @@ export component OfflineManagerView inherits Rectangle {
                         }
                     }
                 }
-                // Open folder + clear all.
                 VerticalLayout {
                     alignment: center;
                     IconBtn {
@@ -201,7 +237,81 @@ export component OfflineManagerView inherits Rectangle {
             }
         }
 
-        // Loading / empty / list.
+        // Toolbar — sort + show-only-failed.
+        HorizontalLayout {
+            vertical-stretch: 0;
+            spacing: 12px;
+            QbzSelect {
+                menu-width: 160px;
+                sm: true;
+                options: [@tr("Sort: A-Z"), @tr("Sort: Recent"), @tr("Sort: Largest"), @tr("Sort: Smallest")];
+                current-index: OfflineManagerState.sort-index;
+                selected(i) => {
+                    OfflineManagerActions.set-sort(i);
+                }
+            }
+            Rectangle {
+                width: failed-label.preferred-width + 28px;
+                height: 32px;
+                border-radius: Radius.sm;
+                border-width: 1px;
+                border-color: OfflineManagerState.show-only-failed ? Theme.accent : Theme.border-subtle;
+                background: OfflineManagerState.show-only-failed ? #e0564f22 : (failed-ta.has-hover ? Theme.surface-elevated : transparent);
+                failed-label := Text {
+                    x: 14px;
+                    text: @tr("Failed only");
+                    color: OfflineManagerState.show-only-failed ? #e0564f : Theme.text-secondary;
+                    font-size: Typography.legal;
+                    vertical-alignment: center;
+                    height: 100%;
+                }
+                failed-ta := TouchArea {
+                    mouse-cursor: pointer;
+                    clicked => {
+                        OfflineManagerActions.toggle-failed();
+                    }
+                }
+            }
+            Rectangle { } // spacer
+        }
+
+        // Body — artist rail + rows.
+        HorizontalLayout {
+            vertical-stretch: 1;
+            spacing: 14px;
+
+            // Left A-Z artist rail.
+            Rectangle {
+                width: 210px;
+                border-radius: Radius.md;
+                background: Theme.surface-card;
+                ScrollView {
+                    VerticalLayout {
+                        padding: 6px;
+                        spacing: 2px;
+                        ArtistRailRow {
+                            name: @tr("All artists");
+                            meta: OfflineManagerState.tracks-count + " tracks";
+                            active: OfflineManagerState.selected-artist == "";
+                            clicked => {
+                                OfflineManagerActions.select-artist("");
+                            }
+                        }
+                        for a in OfflineManagerState.artists: ArtistRailRow {
+                            name: a.name;
+                            meta: a.meta;
+                            active: a.selected;
+                            clicked => {
+                                OfflineManagerActions.select-artist(a.name);
+                            }
+                        }
+                    }
+                }
+            }
+
+            // Right list.
+            Rectangle {
+                horizontal-stretch: 1;
                 if OfflineManagerState.loading: VerticalLayout {
                     alignment: center;
                     HorizontalLayout {
@@ -212,7 +322,7 @@ export component OfflineManagerView inherits Rectangle {
                 if !OfflineManagerState.loading && OfflineManagerState.rows.length == 0: VerticalLayout {
                     alignment: center;
                     Text {
-                text: "No offline tracks yet";
+                        text: @tr("No offline tracks yet");
                         color: Theme.text-muted;
                         font-size: Typography.body;
                         horizontal-alignment: center;
@@ -222,17 +332,36 @@ export component OfflineManagerView inherits Rectangle {
                     VerticalLayout {
                         spacing: 2px;
                         for row in OfflineManagerState.rows: Rectangle {
-                    height: row.kind == "album" ? 58px : 44px;
+                            height: row.kind == "album" ? 60px : 44px;
                             border-radius: 8px;
                             background: row.kind == "album" ? Theme.surface-card : transparent;
                             HorizontalLayout {
-                        padding-left: row.kind == "album" ? 12px : 28px;
+                                padding-left: row.kind == "album" ? 10px : 28px;
                                 padding-right: 12px;
                                 spacing: 12px;
+                                // Album cover (album rows only).
+                                if row.kind == "album": VerticalLayout {
+                                    alignment: center;
+                                    Rectangle {
+                                        width: 40px;
+                                        height: 40px;
+                                        border-radius: 4px;
+                                        clip: true;
+                                        background: Theme.surface-main;
+                                        Image {
+                                            width: 100%;
+                                            height: 100%;
+                                            source: row.cover;
+                                            image-fit: cover;
+                                        }
+                                    }
+                                }
                                 // Status glyph.
                                 VerticalLayout {
                                     alignment: center;
-                            StatusIcon { status: row.status; }
+                                    StatusIcon {
+                                        status: row.status;
+                                    }
                                 }
                                 // Title + subtitle.
                                 VerticalLayout {
@@ -296,4 +425,6 @@ export component OfflineManagerView inherits Rectangle {
                     }
                 }
             }
+        }
+    }
 }

crates/qbz-slint/ui/state.slint

@@ -671,10 +671,19 @@ export struct OfflineRow {
     // 0 none | 2 downloading | 3 ready | 4 failed. Album = worst across tracks.
     status: int,
     progress: float,       // track downloading 0..1
+    cover: image,          // album-header cover (loaded from the on-disk cover.jpg)
+}
+
+// One entry in the manager's left A-Z artist rail.
+export struct OfflineArtist {
+    name: string,
+    meta: string,          // "3 albums · 21 tracks"
+    selected: bool,
 }
 
 export global OfflineManagerState {
     in property <[OfflineRow]> rows: [];
+    in property <[OfflineArtist]> artists: [];
     in property <bool> loading: false;
     // Header stats.
     in property <int> tracks-count: 0;
@@ -682,12 +691,21 @@ export global OfflineManagerState {
     in property <string> limit-text: "";     // "of 5 GB" | "Unlimited"
     in property <float> usage: 0.0;           // 0..1 for the bar (0 = unlimited)
     in-out property <int> limit-gb: 5;        // edit-limit input
+    // Toolbar — set by the controller from the Rust-side filter state so the
+    // dropdown selection / toggle / rail highlight reflect the current view.
+    in property <string> selected-artist: ""; // "" = all artists
+    in property <int> sort-index: 0;           // 0 alpha / 1 recent / 2 largest / 3 smallest
+    in property <bool> show-only-failed: false;
 }
 
 export global OfflineManagerActions {
     // Navigate to the manager (from the Settings "Offline Playback" entry).
     callback open();
     callback refresh();
+    // Toolbar.
+    callback select-artist(string /* name, "" = all */);
+    callback set-sort(int /* index */);
+    callback toggle-failed();
     callback remove-track(string /* track id */);
     callback remove-album(string /* album id */);
     callback redownload-track(string /* track id */);