feat(slint): Qobuz mix detail views (DailyQ / WeeklyQ / FavQ / TopQ)

The For You Qobuz Mixes tiles now open functional mix detail pages.

  - New MixView: header (mix name + description + Play all) over the
    mix's track list (reusing SearchTrackRow). Clicking a track plays
    the whole mix from there; Play all starts at the top.
  - crate::mix resolves each mix to a track list from available
    backend: DailyQ/WeeklyQ -> /dynamic/suggest seeded from the local
    play-history track ids; FavQ -> favorite tracks shuffled (xorshift,
    no rng dep); TopQ -> tracks aggregated from the user's playlists.
    The loaded list is cached so play-all / play-from-track build the
    queue without re-fetching.
  - Backend: ported /dynamic/suggest into qbz-qobuz
    (QobuzClient::get_dynamic_suggest — POST, items parsed leniently
    into Vec<Track>) + QbzCore::get_dynamic_suggest.
  - ContentView.mix + NavEntry::Mix { kind } so each mix is a history
    entry; the tile click records + navigates. New MixTrack artwork
    target. playback::play_tracks generalizes the radio queue builder
    with a start index (radio reuses it at 0).

Tauri's exact generation (listened-track analysis payloads, playlist
play-stats ranking) is approximated; same surfaces + playback, sourced
from the backend the MVP has.

cc

crates/qbz-core/src/core.rs

@@ -1138,6 +1138,21 @@ impl<A: FrontendAdapter + Send + Sync + 'static> QbzCore<A> {
             .map_err(CoreError::Api)
     }
 
+    /// Dynamic mix suggestions (`/dynamic/suggest`) seeded from
+    /// recently-listened track ids. Returns the suggested tracks.
+    pub async fn get_dynamic_suggest(
+        &self,
+        listened_track_ids: &[u64],
+        limit: u32,
+    ) -> Result<Vec<Track>, CoreError> {
+        let client = self.client.read().await;
+        let client = client.as_ref().ok_or(CoreError::NotInitialized)?;
+        client
+            .get_dynamic_suggest(listened_track_ids, limit)
+            .await
+            .map_err(CoreError::Api)
+    }
+
     /// Smart artist radio via the local `qbz-radio` pool builder — a
     /// richer alternative to the Qobuz `/radio/artist` endpoint. Builds
     /// a session pool (seed tracks + similar artists + second-degree)