merge: Most Played Albums (feature/most-played-albums)

Play-count album history store (album_play_history, WAL per ADR-002) hooked
into record_recent, Most Played Albums carousel on Home + For You (default
off), View-all page with search + per-card play count, i18n in all 8
locales.

Conflicts resolved against pre-release: kept the Slint-era Pinned section
alongside the new MostPlayedAlbums everywhere (DiscoverySectionId, prefs,
render kinds, nav, ContentView, HomeActions); AlbumCardItem carries both
is_pinned and plays (populated via card_to_item); .po files union-merged,
msgfmt clean; discover_prefs tests updated (home 15/8 ON, forYou 14/13 ON)
— 10/10 green. Release build green.

km

crates/qbz-ui/ui/state.slint

@@ -35,6 +35,8 @@ export struct AlbumCardItem {
     quality-detail: string,// "24-bit / 96 kHz" — bare detail for QualityBadgeFull
     track-count: string,   // "12" — TRACKS column
     plain-year: string,    // "1973" — bare year for the list-row YEAR column
+    plays: int,            // play count — shown ONLY in the Most Played Albums
+                           // View-all (0 elsewhere, so no count is drawn).
 }
 
 // One entry in an A-Z jump strip (favorites tracks name-group / albums
@@ -223,6 +225,9 @@ export global HomeState {
     // reorders HomeState.favorite-albums in place when this changes.
     in-out property <int> library-albums-sort: 0;
     in property <DiscoverSection> release-watch;
+    // Most Played Albums rail — top albums by local play count (title set by
+    // Rust from `album_play_history::top_albums`). Self-hides while empty.
+    in property <DiscoverSection> most-played-albums;
     in property <[SlimItem]> top-artists: [];
     // Qobuz Playlists row (Home + Editor's Picks). Single-cover cards; the
     // active tab's set is swapped in by crate::home::select_tab.
@@ -254,6 +259,9 @@ export global HomeActions {
     // "View all" on the Qobuz Playlists rail -> the full-page playlist
     // browse (PlaylistBrowseView); a fresh open resets its tag to All.
     callback open-playlist-browse();
+    // Opens the full "Most Played Albums" page (MostPlayedAlbumsView), fed
+    // from the local play-count store.
+    callback open-most-played-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
@@ -276,6 +284,21 @@ export global RecentAlbumsState {
     in property <bool> loading: false;
 }
 
+// MostPlayedAlbumsView — the full "Most Played Albums" page opened from the
+// rail's "View all". Ranked by local play count; each item carries its
+// `plays`. `search` filters title/artist client-side (visibility only).
+export global MostPlayedAlbumsState {
+    in property <[AlbumCardItem]> albums: [];
+    in property <bool> loading: false;
+    in-out property <string> search: "";
+}
+
+export global MostPlayedAlbumsActions {
+    // Filter the loaded page by title/artist. Rust re-sets `albums` to the
+    // matches and re-fires their artwork (mirrors the Qobuz-playlists filter).
+    callback filter(string);
+}
+
 // ---------------------------------------------------------------------------
 // Discover section configurator (Slice 5) — prefs-driven render loop + modal.
 // ---------------------------------------------------------------------------
@@ -430,6 +453,9 @@ export global ForYouState {
     in property <DiscoverSection> recent-albums;
     // Favorite Albums — the user's favorited albums (For You #6).
     in property <DiscoverSection> favorite-albums;
+    // Most Played Albums — top albums by local play count (same data as
+    // HomeState.most-played-albums; local, not tab-specific).
+    in property <DiscoverSection> most-played-albums;
     in property <[SlimItem]> recent-tracks: [];
     in property <[SlimItem]> top-artists: [];
     in property <[SlimItem]> artists-to-follow: [];
@@ -1083,7 +1109,7 @@ export global DragActions {
 }
 
 // Which content view the shell shows.
-export enum ContentView { home, album, artist, artist-releases, settings, search, musician, label, label-releases, award, award-albums, location, favorites, mix, playlist, discover-browse, playlist-browse, recent-albums, playlist-manager, offline-manager, blacklist-manager, local-library, local-album, mixtapes, collections, mixtape-detail, discography-builder, purchases, purchase-album, now-playing }
+export enum ContentView { home, album, artist, artist-releases, settings, search, musician, label, label-releases, award, award-albums, location, favorites, mix, playlist, discover-browse, playlist-browse, recent-albums, most-played-albums, playlist-manager, offline-manager, blacklist-manager, local-library, local-album, mixtapes, collections, mixtape-detail, discography-builder, purchases, purchase-album, now-playing }
 
 // In-app toast (transient notification). Mirrors Tauri's toastStore:
 // a single toast at a time (a new one replaces the current), auto-hidden