feat(locallibrary): Folders tab (flat) — folder-grouped album grid

Fills the Folders tab: a full-loaded grid of albums grouped by directory
(get_albums_with_full_filter), via the shared AlbumCollectionView (grid +
source badge), covers loaded from disk, loaded once on first visit. Clicking
a folder album opens its detail + plays it — navigate_local_album and
play_local_album now resolve tracks via fetch_album_tracks_blocking, which
tries the metadata grouping (Albums tab) then the folder grouping (Folders
tab), so both album views work. New ArtworkTarget::LocalFolderCard applies
covers to the folders model.

Tree mode (two-pane lazy folder tree) + folder search/sort are later slices.

cc

crates/qbz-slint/src/artwork.rs

@@ -83,6 +83,8 @@ pub enum ArtworkTarget {
     /// is the albums generation at fetch time; a stale cover (the model was
     /// replaced by a search/sort/retry) is dropped on apply.
     LocalAlbumCard { index: usize, gen: u64 },
+    /// A card in LocalLibraryState.folders[index] (Folders-flat grid).
+    LocalFolderCard { index: usize },
     /// A card in FavoritesState.artists[index].
     FavoriteArtist { index: usize },
     /// A card in FavoritesState.labels[index].
@@ -613,6 +615,13 @@ fn apply_artwork(
                 model.set_row_data(index, item);
             }
         }
+        ArtworkTarget::LocalFolderCard { index } => {
+            let model = window.global::<crate::LocalLibraryState>().get_folders();
+            if let Some(mut item) = model.row_data(index) {
+                item.artwork = image;
+                model.set_row_data(index, item);
+            }
+        }
         ArtworkTarget::FavoriteArtist { index } => {
             let model = window.global::<crate::FavoritesState>().get_artists();
             if let Some(mut item) = model.row_data(index) {

crates/qbz-slint/src/local_library.rs

@@ -670,6 +670,86 @@ pub fn apply_local_album(
     s.set_loading(false);
 }
 
+// ============================ Folders (flat) ==============================
+//
+// The Folders tab (flat mode) is the album grid grouped by directory rather
+// than by metadata. Full-load (folder counts are bounded; the freeze risk is
+// the Tracks table). Reuses AlbumCollectionView; covers load per card.
+
+fn fetch_folder_albums() -> Vec<crate::album_map::AlbumCard> {
+    crate::library_db::with_db(|db| {
+        db.get_albums_with_full_filter(
+            /* include_hidden */ false,
+            /* include_qobuz_downloads */ true,
+            /* exclude_network_folders */ false,
+        )
+    })
+    .unwrap_or_default()
+    .into_iter()
+    .map(map_local_album)
+    .collect()
+}
+
+fn folder_artwork_jobs(cards: &[crate::album_map::AlbumCard]) -> Vec<ArtworkJob> {
+    cards
+        .iter()
+        .enumerate()
+        .filter(|(_, c)| !c.artwork_url.is_empty())
+        .map(|(i, c)| ArtworkJob {
+            target: ArtworkTarget::LocalFolderCard { index: i },
+            url: c.artwork_url.clone(),
+        })
+        .collect()
+}
+
+fn apply_folders(window: &AppWindow, cards: Vec<crate::album_map::AlbumCard>) {
+    let items: Vec<AlbumCardItem> = cards.into_iter().map(crate::album_map::to_item).collect();
+    let s = window.global::<LocalLibraryState>();
+    s.set_folders(ModelRc::new(VecModel::from(items)));
+    s.set_folders_loading(false);
+    s.set_folders_load_failed(false);
+}
+
+/// Load the folder-grouped album grid on first visit (re-entry keeps it).
+pub fn ensure_folders_loaded(
+    weak: slint::Weak<AppWindow>,
+    handle: tokio::runtime::Handle,
+    image_cache: ImageCache,
+) {
+    let _ = weak.upgrade_in_event_loop(move |w| {
+        let s = w.global::<LocalLibraryState>();
+        if s.get_folders().row_count() != 0 || s.get_folders_loading() {
+            return;
+        }
+        s.set_folders_loading(true);
+        s.set_folders_load_failed(false);
+        let weak2 = w.as_weak();
+        handle.spawn(async move {
+            let cards = tokio::task::spawn_blocking(fetch_folder_albums)
+                .await
+                .unwrap_or_default();
+            let _ = weak2.upgrade_in_event_loop(move |w| {
+                let jobs = folder_artwork_jobs(&cards);
+                apply_folders(&w, cards);
+                crate::artwork::spawn_local_loads(jobs, w.as_weak(), image_cache);
+            });
+        });
+    });
+}
+
+/// Fetch an album's tracks by group key, trying the metadata grouping first
+/// (Albums tab) then the folder grouping (Folders tab). Blocking.
+pub fn fetch_album_tracks_blocking(group_key: &str) -> Vec<qbz_library::LocalTrack> {
+    crate::library_db::with_db(|db| {
+        let meta = db.get_album_tracks_metadata(group_key)?;
+        if !meta.is_empty() {
+            return Ok(meta);
+        }
+        db.get_album_tracks(group_key)
+    })
+    .unwrap_or_default()
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/qbz-slint/src/main.rs

@@ -433,8 +433,7 @@ fn navigate_local_album(
         });
         let gk = group_key.clone();
         let tracks = tokio::task::spawn_blocking(move || {
-            let mut t = crate::library_db::with_db(|db| db.get_album_tracks_metadata(&gk))
-                .unwrap_or_default();
+            let mut t = local_library::fetch_album_tracks_blocking(&gk);
             playback::fill_missing_covers(&mut t);
             t
         })
@@ -966,6 +965,9 @@ fn navigate_local_library(
         local_library::LibTab::Albums => {
             local_library::ensure_albums_loaded(weak, handle.clone(), image_cache);
         }
+        local_library::LibTab::Folders => {
+            local_library::ensure_folders_loaded(weak, handle.clone(), image_cache);
+        }
         local_library::LibTab::Tracks => {
             local_library::ensure_tracks_loaded(weak, handle.clone());
         }

crates/qbz-slint/src/playback.rs

@@ -226,8 +226,7 @@ pub fn play_local_album(
 ) {
     handle.spawn(async move {
         let tracks = tokio::task::spawn_blocking(move || {
-            let mut tracks = crate::library_db::with_db(|db| db.get_album_tracks_metadata(&album_id))
-                .unwrap_or_default();
+            let mut tracks = crate::local_library::fetch_album_tracks_blocking(&album_id);
             fill_missing_covers(&mut tracks);
             tracks
         })

crates/qbz-slint/ui/locallibrary/LocalLibraryView.slint

@@ -536,9 +536,71 @@ export component LocalLibraryView inherits Rectangle {
                 }
             }
 
+            // -------- Folders tab (flat) — folder-grouped album grid -----
+            if LocalLibraryState.active-tab == "folders": Rectangle {
+                if LocalLibraryState.folders-loading: VerticalLayout {
+                    alignment: center;
+                    HorizontalLayout {
+                        alignment: center;
+                        LoadingSpinner { size: 36px; }
+                    }
+                }
+                if !LocalLibraryState.folders-loading
+                    && LocalLibraryState.folders.length == 0: VerticalLayout {
+                    alignment: center;
+                    Text {
+                        text: @tr("No folders in your local library yet.");
+                        color: Theme.text-muted;
+                        font-size: Typography.body;
+                        horizontal-alignment: center;
+                    }
+                }
+                if !LocalLibraryState.folders-loading
+                    && LocalLibraryState.folders.length > 0: Rectangle {
+                    folders-flick := Flickable {
+                        viewport-width: self.width;
+                        viewport-height: folders-page.preferred-height;
+                        folders-page := VerticalLayout {
+                            width: parent.width;
+                            padding-left: 32px;
+                            padding-right: 32px;
+                            padding-top: 16px;
+                            padding-bottom: 100px;
+                            alignment: start;
+                            AlbumCollectionView {
+                                albums: LocalLibraryState.folders;
+                                is-grouped: false;
+                                view-mode: "grid";
+                                show-source: false;
+                                show-favorite: false;
+                                show-source-badge: true;
+                                open-album(id) => {
+                                    LocalLibraryActions.open-album(id);
+                                }
+                                open-artist(id) => {
+                                    LocalLibraryActions.open-artist(id);
+                                }
+                                media-action(kind, id, action) => {
+                                    LocalLibraryActions.album-action(id, action);
+                                }
+                            }
+                        }
+                    }
+                    ListScrollbar {
+                        x: parent.width - self.width - 4px;
+                        width: 14px;
+                        height: 100%;
+                        viewport-height: folders-flick.viewport-height;
+                        visible-height: folders-flick.height;
+                        viewport-y <=> folders-flick.viewport-y;
+                    }
+                }
+            }
+
             // -------- Other tabs — placeholder until their slices land ----
             if LocalLibraryState.active-tab != "albums"
-                && LocalLibraryState.active-tab != "tracks": VerticalLayout {
+                && LocalLibraryState.active-tab != "tracks"
+                && LocalLibraryState.active-tab != "folders": VerticalLayout {
                 alignment: center;
                 spacing: 6px;
                 Text {

crates/qbz-slint/ui/state.slint

@@ -377,6 +377,11 @@ export global LocalLibraryState {
     in property <bool> tracks-load-failed: false;
     in-out property <int> tracks-next-offset: 0;
     in-out property <string> tracks-search: "";
+
+    // --- Folders tab (flat) — albums grouped by directory (full load) ---
+    in property <[AlbumCardItem]> folders: [];
+    in property <bool> folders-loading: false;
+    in property <bool> folders-load-failed: false;
 }
 
 export global LocalLibraryActions {