feat: artist/page endpoint, multi-disc fix, playlist ownership, UX improvements

- Switch artist view to artist/page API (proper sections: Albums, Singles & EPs,
  Live, Compilations; version in titles like "Deluxe")
- Fix artist sections categorization using releases[].type from artist/page
- Add getUser() backend call; fetch on session restore when userId=0 to fix
  playlist ownership (Remove from playlist / Delete playlist were missing)
- Fix multi-disc double-click / Play Now queue start index (disc headers were
  counted in row index but excluded from currentTracksJson)
- Hide redundant Album column when viewing an album
- Make artist name in context header clickable (navigates to artist page)
- Fix gap between title and artist name in context header (addStretch)
- Fix queue panel track titles to include version field
- Fix album list to show version in title column

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

rust/src/lib.rs

@@ -239,7 +239,7 @@ pub unsafe extern "C" fn qobuz_backend_get_artist(ptr: *mut Backend, artist_id:
     let cb = inner.cb; let ud = inner.ud;
 
     spawn(inner, async move {
-        let result = client.lock().await.get_artist(artist_id).await;
+        let result = client.lock().await.get_artist_page(artist_id).await;
         let (ev, json) = match result {
             Ok(r)  => (EV_ARTIST_OK,  serde_json::to_string(&r).unwrap_or_default()),
             Err(e) => (EV_ARTIST_ERR, err_json(&e.to_string())),
@@ -563,6 +563,25 @@ pub unsafe extern "C" fn qobuz_backend_remove_fav_album(ptr: *mut Backend, album
     });
 }
 
+// ---------- User ----------
+
+pub const EV_USER_OK: c_int = 23;
+
+#[no_mangle]
+pub unsafe extern "C" fn qobuz_backend_get_user(ptr: *mut Backend) {
+    let inner = &(*ptr).0;
+    let client = inner.client.clone();
+    let cb = inner.cb; let ud = inner.ud;
+    spawn(inner, async move {
+        let result = client.lock().await.get_user().await;
+        let (ev, json) = match result {
+            Ok(r)  => (EV_USER_OK, serde_json::to_string(&r).unwrap_or_default()),
+            Err(e) => (EV_GENERIC_ERR, err_json(&e.to_string())),
+        };
+        call_cb(cb, ud, ev, &json);
+    });
+}
+
 // ---------- Playlist management ----------
 
 pub const EV_PLAYLIST_CREATED: c_int = 20;