feat(label): redesign label detail view with Android-style sections

Replace the flat album grid LabelView with a rich detail page featuring:
- Header with label image, name, description, and play button
- Popular Tracks section (5/10/all expand, same UX as ArtistDetailView)
- Releases horizontal scroll row with "See all" → LabelReleasesView
- Critics' Picks section from second releases container
- Playlists, Artists, and More Labels sections

Backend: add /label/page and /label/explore API endpoints with V2
commands (v2_get_label_page, v2_get_label_explore). Models use
serde_json::Value for flexible section parsing.

Old LabelView renamed to LabelReleasesView for the "See all" flow.
i18n keys added to all 4 locales (en, es, de, fr).

crates/qbz-models/src/lib.rs

@@ -42,7 +42,8 @@ pub use playback::{PlaybackState, PlaybackStatus, QueueState, QueueTrack, Repeat
 pub use traits::{FrontendAdapter, LoggingAdapter, NoOpAdapter};
 pub use types::{
     Album, AlbumSummary, Artist, ArtistAlbums, ArtistBiography, Favorites, Genre, GenreInfo,
-    GenreListContainer, GenreListResponse, ImageSet, Label, LabelDetail, Playlist,
+    GenreListContainer, GenreListResponse, ImageSet, Label, LabelDetail,
+    LabelExploreResponse, LabelPageContainer, LabelPageData, LabelPageGenericList, Playlist,
     PlaylistDuplicateResult, PlaylistGenre, PlaylistOwner, PlaylistWithTrackIds, Quality,
     SearchResults, SearchResultsPage, StreamRestriction, StreamUrl, Track, TracksContainer,
     UserSession,

crates/qbz-models/src/types.rs

@@ -353,6 +353,47 @@ pub struct LabelDetail {
     pub albums_count: Option<u32>,
 }
 
+// ============ Label Page Types (/label/page) ============
+
+/// Top-level response from /label/page
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct LabelPageData {
+    pub id: u64,
+    pub name: String,
+    pub description: Option<String>,
+    #[serde(default)]
+    pub image: Option<serde_json::Value>,
+    #[serde(default)]
+    pub releases: Option<Vec<LabelPageContainer>>,
+    #[serde(default)]
+    pub playlists: Option<LabelPageGenericList>,
+    #[serde(default)]
+    pub top_tracks: Option<Vec<serde_json::Value>>,
+    #[serde(default)]
+    pub top_artists: Option<LabelPageGenericList>,
+}
+
+/// A container within label page (e.g. releases category)
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct LabelPageContainer {
+    pub id: Option<String>,
+    pub data: Option<LabelPageGenericList>,
+}
+
+/// Generic list with has_more and items
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct LabelPageGenericList {
+    pub has_more: Option<bool>,
+    pub items: Option<Vec<serde_json::Value>>,
+}
+
+/// Response from /label/explore
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct LabelExploreResponse {
+    pub has_more: Option<bool>,
+    pub items: Option<Vec<serde_json::Value>>,
+}
+
 /// Genre model
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct Genre {