feat(reco): Recommendations in all Discover flyouts + opt-out setting

Surface the new Recommendations tab everywhere Discover sub-sections are listed,
and make it opt-out.

- Flyouts: the sidebar section-nav flyout and both header nav flyouts (full text
  + compact icon) now list "Recommendations" alongside Home / Editor's Picks /
  For You. The Rust route handler already maps "discover-recommendations"
  (strip_prefix + select_tab + ensure_loaded), so no routing change was needed.
- Opt-out: a show_recommendations flag (default on) persisted in the per-user
  discover-prefs store (qbz_app), seeded into SettingsState on session start.
  Settings > Integrations gains a "Show Recommendations in Discover" toggle whose
  description nudges connecting Last.fm + ListenBrainz (MusicBrainz is used
  automatically to match releases). Off => the tab pill and every flyout entry
  disappear.
- Gating uses two mounted instances per flyout (one with the entry, one without)
  because Slint can't type-infer [NavMenuEntry] from a ternary of array literals;
  the HomeView pill uses a plain if.

cargo check -p qbz green.

cc

crates/qbz-app/src/settings/discover_prefs.rs

@@ -157,6 +157,8 @@ pub struct DiscoverPrefs {
     pub home: Vec<SectionPref>,
     pub editor_picks: Vec<SectionPref>,
     pub for_you: Vec<SectionPref>,
+    /// Opt-out: show the external "Recommendations" tab in Discover. Default on.
+    pub show_recommendations: bool,
 }
 
 /// The exact `DEFAULT_PREFS` from `sectionPrefs.ts`.
@@ -204,6 +206,7 @@ pub fn default_prefs() -> DiscoverPrefs {
             pref(ArtistsToFollow, true),
             pref(ArtistSpotlight, true),
         ],
+        show_recommendations: true,
     }
 }
 
@@ -295,6 +298,7 @@ impl DiscoverPrefs {
             "home": arr(&self.home),
             "editorPicks": arr(&self.editor_picks),
             "forYou": arr(&self.for_you),
+            "showRecommendations": self.show_recommendations,
         })
     }
 
@@ -313,6 +317,8 @@ impl DiscoverPrefs {
                 home: reconcile_list(Some(arr), &defaults.home),
                 editor_picks: defaults.editor_picks,
                 for_you: defaults.for_you,
+                // Legacy V1 (home-only array) predates the flag -> default on.
+                show_recommendations: true,
             }
         } else if value.is_object() {
             let get = |key: &str| value.get(key).and_then(|v| v.as_array());
@@ -320,6 +326,11 @@ impl DiscoverPrefs {
                 home: reconcile_list(get("home"), &defaults.home),
                 editor_picks: reconcile_list(get("editorPicks"), &defaults.editor_picks),
                 for_you: reconcile_list(get("forYou"), &defaults.for_you),
+                // Missing key (older persisted blob) -> default on.
+                show_recommendations: value
+                    .get("showRecommendations")
+                    .and_then(|v| v.as_bool())
+                    .unwrap_or(true),
             }
         } else {
             defaults

crates/qbz-ui/ui/discover/HomeView.slint

@@ -8,7 +8,7 @@
 
 import { Theme } from "../foundation/semantic-colors.slint";
 import { Typography } from "../foundation/typography.slint";
-import { HomeState, HomeActions, DiscoverState, DiscoverActions, GenreFilterState, GenreFilterActions, NavState, ContentView, ShellState } from "../state.slint";
+import { HomeState, HomeActions, DiscoverState, DiscoverActions, GenreFilterState, GenreFilterActions, NavState, ContentView, ShellState, SettingsState } from "../state.slint";
 import { Carousel } from "Carousel.slint";
 import { SlimCarousel } from "SlimCarousel.slint";
 import { PlaylistCarousel } from "PlaylistCarousel.slint";
@@ -211,7 +211,7 @@ export component HomeView inherits Rectangle {
                             active: HomeState.active-tab == "forYou";
                             clicked => { HomeActions.select-tab("forYou"); }
                         }
-                        Tab {
+                        if SettingsState.show-recommendations: Tab {
                             label: @tr("Recommendations");
                             active: HomeState.active-tab == "recommendations";
                             clicked => { HomeActions.select-tab("recommendations"); }

crates/qbz-ui/ui/settings/IntegrationsSettings.slint

@@ -8,7 +8,7 @@
 import { Theme } from "../foundation/semantic-colors.slint";
 import { Typography } from "../foundation/typography.slint";
 import { Radius } from "../foundation/radius.slint";
-import { ScrobbleState, ScrobbleActions, DiscordState } from "../state.slint";
+import { ScrobbleState, ScrobbleActions, DiscordState, SettingsState } from "../state.slint";
 import { SettingRow } from "SettingRow.slint";
 import { QbzIcon } from "../primitives/QbzIcon.slint";
 import { QbzToggle } from "../primitives/QbzToggle.slint";
@@ -62,10 +62,30 @@ component SecondaryButton inherits Rectangle {
 export component IntegrationsSettings inherits VerticalLayout {
     spacing: 4px;
 
+    // Bubbles a persisted bool toggle up to SettingsView -> Rust handle_bool.
+    callback settings-bool(string, bool);
+
     init => {
         ScrobbleActions.load();
     }
 
+    // ===================================================================
+    // RECOMMENDATIONS — opt-out for the external Discover "Recommendations"
+    // tab. The description nudges connecting the sources that feed it.
+    // ===================================================================
+    GroupHeader { text: @tr("RECOMMENDATIONS"); }
+    SettingRow {
+        label: @tr("Show Recommendations in Discover");
+        description: @tr("A personalized Discover tab built from your listening. For the best results connect Last.fm and ListenBrainz below — MusicBrainz is used automatically to match releases.");
+        QbzToggle {
+            checked: SettingsState.show-recommendations;
+            toggled(v) => {
+                SettingsState.show-recommendations = v;
+                root.settings-bool("show-recommendations", v);
+            }
+        }
+    }
+
     // ===================================================================
     // SCROBBLERS — master header: title + master toggle + collapse chevron.
     // Body renders only when `enabled && !ui-collapsed`.

crates/qbz-ui/ui/settings/SettingsView.slint

@@ -246,7 +246,11 @@ export component SettingsView inherits Rectangle {
                     }
                     if !SettingsState.loading && SettingsState.section == 4: LocalLibrarySettings { }
                     if !SettingsState.loading && SettingsState.section == 7: ContentFilteringSettings { }
-                    if !SettingsState.loading && SettingsState.section == 6: IntegrationsSettings { }
+                    if !SettingsState.loading && SettingsState.section == 6: IntegrationsSettings {
+                        settings-bool(k, v) => {
+                            root.settings-bool(k, v);
+                        }
+                    }
                     if !SettingsState.loading && SettingsState.section == 5: DeveloperSettings { }
                 }
             }

crates/qbz-ui/ui/shell/HeaderBar.slint

@@ -768,7 +768,27 @@ export component HeaderBar inherits Rectangle {
             Rectangle { width: 6px; }
             // Qobuz-only — HIDDEN entirely while offline (ADR-010 `if` at
             // the mount site, not rendered-disabled).
-            if !OfflineState.offline: VerticalLayout {
+            // Discover. Two mounts (Slint can't infer [NavMenuEntry] from a
+            // ternary of array literals): WITH the opt-in Recommendations entry,
+            // or without, gated by the opt-out setting.
+            if !OfflineState.offline && SettingsState.show-recommendations: VerticalLayout {
+                alignment: center;
+                NavTabWithMenu {
+                    tab-index: 0;
+                    icon: @image-url("../assets/icons/compass.svg");
+                    label: @tr("Discover");
+                    active: true;
+                    show-icon: root.show-tab-icons;
+                    home-item: 0;
+                    items: [
+                        { label: @tr("Home"), has-glyph: false, route: "discover-home" },
+                        { label: @tr("Editor's Picks"), has-glyph: false, route: "discover-editorPicks" },
+                        { label: @tr("For You"), has-glyph: false, route: "discover-forYou" },
+                        { label: @tr("Recommendations"), has-glyph: false, route: "discover-recommendations" },
+                    ];
+                }
+            }
+            if !OfflineState.offline && !SettingsState.show-recommendations: VerticalLayout {
                 alignment: center;
                 NavTabWithMenu {
                     tab-index: 0;
@@ -861,7 +881,25 @@ export component HeaderBar inherits Rectangle {
             Rectangle { width: 6px; }
             // Qobuz-only — HIDDEN entirely while offline (ADR-010 `if` at
             // the mount site, not rendered-disabled).
-            if !OfflineState.offline: VerticalLayout {
+            // Discover. Two mounts (Slint can't infer [NavMenuEntry] from a
+            // ternary of array literals): WITH the opt-in Recommendations entry,
+            // or without, gated by the opt-out setting.
+            if !OfflineState.offline && SettingsState.show-recommendations: VerticalLayout {
+                alignment: center;
+                CompactNavBtn {
+                    tab-index: 0;
+                    title: @tr("Discover");
+                    icon: @image-url("../assets/icons/compass.svg");
+                    home-item: 0;
+                    items: [
+                        { label: @tr("Home"), has-glyph: false, route: "discover-home" },
+                        { label: @tr("Editor's Picks"), has-glyph: false, route: "discover-editorPicks" },
+                        { label: @tr("For You"), has-glyph: false, route: "discover-forYou" },
+                        { label: @tr("Recommendations"), has-glyph: false, route: "discover-recommendations" },
+                    ];
+                }
+            }
+            if !OfflineState.offline && !SettingsState.show-recommendations: VerticalLayout {
                 alignment: center;
                 CompactNavBtn {
                     tab-index: 0;

crates/qbz-ui/ui/shell/Sidebar.slint

@@ -16,7 +16,7 @@ import { QbzIcon } from "../primitives/QbzIcon.slint";
 import { SidebarPlaylistCollage } from "../primitives/SidebarPlaylistCollage.slint";
 import { ContextMenu } from "../primitives/ContextMenu.slint";
 import { ContextMenuItem } from "../primitives/ContextMenuItem.slint";
-import { ShellState, SidebarState, SidebarActions, SidebarEntry, DragState, HeaderMenuState, NavMenuEntry, SidebarFolderPopupState, SidebarTooltipState, MyQbzBrandingState, OfflineState, NavState, ContentView, AppearanceState } from "../state.slint";
+import { ShellState, SidebarState, SidebarActions, SidebarEntry, DragState, HeaderMenuState, NavMenuEntry, SidebarFolderPopupState, SidebarTooltipState, MyQbzBrandingState, OfflineState, NavState, ContentView, AppearanceState, SettingsState } from "../state.slint";
 import { ScrollView, LineEdit } from "std-widgets.slint";
 
 // A single context-menu item row.
@@ -703,7 +703,22 @@ export component Sidebar inherits Rectangle {
             spacing: 2px;
             // Qobuz-only section — HIDDEN entirely while offline (Local
             // Library and My QBZ below stay; ADR-010 `if` at the mount site).
-            if !OfflineState.offline: SidebarNavRow {
+            // Discover. Two mounts because Slint can't infer [NavMenuEntry] from
+            // a ternary of array literals: one WITH the opt-in Recommendations
+            // entry, one without, gated by the opt-out setting.
+            if !OfflineState.offline && SettingsState.show-recommendations: SidebarNavRow {
+                tab-index: 0;
+                icon: @image-url("../assets/icons/compass.svg");
+                label: @tr("Discover");
+                home-item: 0;
+                items: [
+                    { label: @tr("Home"), has-glyph: false, route: "discover-home" },
+                    { label: @tr("Editor's Picks"), has-glyph: false, route: "discover-editorPicks" },
+                    { label: @tr("For You"), has-glyph: false, route: "discover-forYou" },
+                    { label: @tr("Recommendations"), has-glyph: false, route: "discover-recommendations" },
+                ];
+            }
+            if !OfflineState.offline && !SettingsState.show-recommendations: SidebarNavRow {
                 tab-index: 0;
                 icon: @image-url("../assets/icons/compass.svg");
                 label: @tr("Discover");

crates/qbz-ui/ui/state.slint

@@ -2714,6 +2714,9 @@ export global SettingsState {
     in-out property <bool> resume-position: false;
     in-out property <bool> gapless: true;
     in-out property <bool> stream-uncached: false;
+    // Discover — opt-out: show the external "Recommendations" tab. Default on.
+    // Seeded from persisted discover prefs at session start (crate::discover_prefs).
+    in-out property <bool> show-recommendations: true;
     in-out property <bool> streaming-only: false;
     // Volume normalization (loudness leveling). Applied in the shared player
     // and bypassed automatically when bit-perfect is active. Surfaced in the

crates/qbz/src/discover_prefs.rs

@@ -27,7 +27,7 @@ use qbz_app::settings::discover_prefs::{
 use slint::{ComponentHandle, ModelRc, SharedString, VecModel};
 
 use crate::artwork::{ImageCache, spawn_loads};
-use crate::{AppWindow, ConfigRow, DiscoverSection, DiscoverState, SectionDescriptor};
+use crate::{AppWindow, ConfigRow, DiscoverSection, DiscoverState, SectionDescriptor, SettingsState};
 
 /// Per-user persistent store. `None` outside an active session.
 static STORE: Mutex<Option<DiscoverPrefsStore>> = Mutex::new(None);
@@ -77,6 +77,16 @@ fn persist() {
     }
 }
 
+/// Opt-out toggle for the Discover "Recommendations" tab (Settings > Integrations).
+/// The Slint `SettingsState.show-recommendations` global is updated by the toggle
+/// itself; this writes the choice through to the persisted prefs.
+pub fn set_show_recommendations(value: bool) {
+    if let Some(p) = PREFS.lock().unwrap().as_mut() {
+        p.show_recommendations = value;
+    }
+    persist();
+}
+
 // ---------------------------------------------------------------------------
 // id -> render kind / i18n label key
 // ---------------------------------------------------------------------------
@@ -222,6 +232,9 @@ pub fn push_config_rows(window: &AppWindow, prefs: &DiscoverPrefs, tab: Discover
 /// the first `apply_home`. Mirrors `myqbz_prefs::seed`.
 pub fn seed(window: &AppWindow) {
     let prefs = current();
+    window
+        .global::<SettingsState>()
+        .set_show_recommendations(prefs.show_recommendations);
     push_descriptors(window, &prefs);
 }
 

crates/qbz/src/settings.rs

@@ -867,6 +867,10 @@ pub async fn handle_bool(
         "show-context-icon" => {
             with_playback(&ctx.playback, |s| s.set_show_context_icon(value)).map(|_| Apply::None)
         }
+        "show-recommendations" => {
+            crate::discover_prefs::set_show_recommendations(value);
+            Ok(Apply::None)
+        }
         "persist-session" => {
             let r = with_playback(&ctx.playback, |s| s.set_persist_session(value))
                 .map(|_| Apply::None);