refactor(labels): purge legacy /label/get stack

/label/get is gone from the Qobuz v9.7.0.3 Android app (source:
c30/b.java doesn't declare it anymore). With the Qobuz beta rollout
the server-side deprecation timer is probably running, so we yank our
dependency now.

Removed:
- LABEL_GET path constant (qbz-qobuz + src-tauri/api)
- get_label() client method (qbz-qobuz + src-tauri/api)
- get_label() wrapper in QbzCore + CoreBridge
- v2_get_label tauri command + its lib.rs registration
- LabelDetail backend type (qbz-models + src-tauri/api/models)
- commands::search::get_label (dead, was never registered)
- Unused LabelDetail import in src/routes/+page.svelte

Preserved:
- Frontend LabelDetail interface (it's a UI view-model shaped by
  LabelReleasesView, not a backend contract)
- /api/labels/{id} HTTP route on qbzd — now composes /label/page +
  /label/getAlbums internally so external HTTP clients still see the
  same { id, name, description, image, albums: { items, total, ... } }
  shape

cc

crates/qbz-core/src/core.rs

@@ -8,8 +8,8 @@ use tokio::sync::RwLock;
 
 use qbz_models::{
     Album, Artist, CoreEvent, DiscoverAlbum, DiscoverData, DiscoverPlaylistsResponse,
-    DiscoverResponse, FrontendAdapter, GenreInfo, LabelDetail, LabelExploreResponse,
-    LabelGetListResponse, LabelListPage, LabelPageData, LabelStoryResponse, PageArtistResponse,
+    DiscoverResponse, FrontendAdapter, GenreInfo, LabelExploreResponse, LabelGetListResponse,
+    LabelListPage, LabelPageData, LabelStoryResponse, PageArtistResponse,
     Playlist, PlaylistTag, Quality, QueueState, QueueTrack, RepeatMode, SearchResultsPage,
     StreamUrl, Track, UserSession,
 };
@@ -838,22 +838,6 @@ impl<A: FrontendAdapter + Send + Sync + 'static> QbzCore<A> {
             .map_err(CoreError::Api)
     }
 
-    /// Get label details
-    pub async fn get_label(
-        &self,
-        label_id: u64,
-        limit: u32,
-        offset: u32,
-    ) -> Result<LabelDetail, CoreError> {
-        let client = self.client.read().await;
-        let client = client.as_ref().ok_or(CoreError::NotInitialized)?;
-
-        client
-            .get_label(label_id, limit, offset)
-            .await
-            .map_err(CoreError::Api)
-    }
-
     /// Get label page (aggregated: top tracks, releases, playlists, artists)
     pub async fn get_label_page(&self, label_id: u64) -> Result<LabelPageData, CoreError> {
         let client = self.client.read().await;