feat(home): auto-refresh recently-played rails + a row refresh button

Home's recently-played albums/tracks only populated on a full home load, so
tracks played mid-session never appeared until restart. Re-read the LOCAL
store into the rails when a track is recorded while Home is visible, and on
Home re-mount if it went dirty — event-driven, no polling, cheap (small JSON
read + cached artwork). Also add a manual refresh button in each recently-
played row header next to the page chevrons (moved off the top toolbar, where
it crowded the discovery tab bar).

cc

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

@@ -69,9 +69,12 @@ component ViewAllLink inherits Rectangle {
 export component Carousel inherits VerticalLayout {
     in property <DiscoverSection> section;
     in property <bool> show-view-all: false;
+    // Optional refresh affordance in the row header (recently-played rows).
+    in property <bool> show-refresh: false;
     callback album-clicked(string);
     callback media-action(string, string, string);
     callback view-all-clicked();
+    callback refresh-clicked();
 
     property <length> card-width: 200px;
     // Overridable so a host view (Discover Recommendations) can give the row a
@@ -189,6 +192,15 @@ export component Carousel inherits VerticalLayout {
                     }
                 }
             }
+            if root.show-refresh: VerticalLayout {
+                alignment: center;
+                NavButton {
+                    icon: @image-url("../assets/icons/refresh-cw.svg");
+                    clicked => {
+                        root.refresh-clicked();
+                    }
+                }
+            }
             VerticalLayout {
                 alignment: center;
                 NavButton {

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, SettingsState } from "../state.slint";
+import { HomeState, HomeActions, DiscoverState, DiscoverActions, GenreFilterState, GenreFilterActions, NavState, ContentView, ShellState, SettingsState, TooltipState } from "../state.slint";
 import { Carousel } from "Carousel.slint";
 import { SlimCarousel } from "SlimCarousel.slint";
 import { ArtistCarousel } from "ArtistCarousel.slint";
@@ -121,6 +121,9 @@ component GenreButton inherits Rectangle {
     }
 }
 
+// Manual refresh for the recently-played rails — sits in the toolbar next
+// to the nav cluster. Same 32px icon-button form as GearButton, plus the
+// global hover tooltip (TooltipState — the TransportControls pattern).
 component GearButton inherits Rectangle {
     callback clicked();
 
@@ -157,6 +160,14 @@ export component HomeView inherits Rectangle {
 
     background: Theme.surface-main;
 
+    // The view remounts on every navigation to Home (AppShell's `if` mount),
+    // so this is the "Home regained focus" hook: Rust re-reads the LOCAL
+    // recently-played rails only when a play was recorded while Home was
+    // off-screen (dirty-flag gated — otherwise a no-op).
+    init => {
+        HomeActions.home-mounted();
+    }
+
     VerticalLayout {
         spacing: 0px;
 
@@ -390,6 +401,13 @@ export component HomeView inherits Rectangle {
                         // play-history, not a /discover endpoint — so it goes
                         // through its own action, not discover-view-all).
                         show-view-all: true;
+                        // Manual refresh, in the row header next to the page
+                        // chevrons (the recently-played rows are the only ones
+                        // that go stale between full home loads).
+                        show-refresh: true;
+                        refresh-clicked => {
+                            HomeActions.refresh-recent();
+                        }
                         album-clicked(id) => {
                             root.album-clicked(id);
                         }
@@ -410,6 +428,10 @@ export component HomeView inherits Rectangle {
                     if desc.id == "continueListening" && HomeState.recent.length > 0: SlimCarousel {
                         title: @tr("Recently Played Tracks");
                         items: HomeState.recent;
+                        show-refresh: true;
+                        refresh-clicked => {
+                            HomeActions.refresh-recent();
+                        }
                         item-clicked(id) => {
                             root.media-action("track", id, "play");
                         }

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

@@ -52,6 +52,10 @@ export component SlimCarousel inherits VerticalLayout {
     // (recent, popular) are unchanged; only the Weekly rows opt in.
     in property <bool> show-list-actions: false;
     callback list-action(string);
+    // Optional refresh affordance in the row header (recently-played rows).
+    // Shown regardless of page count, unlike the chevrons.
+    in property <bool> show-refresh: false;
+    callback refresh-clicked();
 
     property <int> columns: 4;
     property <int> rows: 3;
@@ -99,6 +103,18 @@ export component SlimCarousel inherits VerticalLayout {
                 }
             }
         }
+        if root.show-refresh: HorizontalLayout {
+            spacing: 4px;
+            VerticalLayout {
+                alignment: center;
+                NavButton {
+                    icon: @image-url("../assets/icons/refresh-cw.svg");
+                    clicked => {
+                        root.refresh-clicked();
+                    }
+                }
+            }
+        }
         // Only when there is a second page.
         if root.total > root.per-page: HorizontalLayout {
             spacing: 4px;

crates/qbz-ui/ui/state.slint

@@ -204,6 +204,14 @@ export global HomeActions {
     // "View all" on the Recently Played Albums rail -> the full-page listing
     // (RecentAlbumsView), fed from the local play-history store.
     callback open-recent-albums();
+    // Fired by HomeView's init on every (re)mount. Rust re-reads the LOCAL
+    // recently-played store into the two rails IF a play was recorded while
+    // Home was off-screen (dirty-flag gated in Rust — a no-op otherwise, so
+    // mounting Home stays free).
+    callback home-mounted();
+    // Manual refresh (the toolbar button next to the nav cluster):
+    // unconditionally re-read the local recently-played rails.
+    callback refresh-recent();
 }
 
 // RecentAlbumsView — the full "Recently Played Albums" page opened from the