fix(flutter): full-player kebab nav + restore artistAlbums SWR

Two unrelated issues, batched.

Full-player kebab → "Go to album/artist" still crashed with
_debugCheckDuplicatedPageKeys despite the prior onBeforeNavigate
fix. Cause: pop() and push() ran in the same frame, so go_router's
page-key reservation table briefly contained both /now-playing AND
the destination shell-child, tripping the duplicate-key assert.

Refactor: replace onBeforeNavigate with onNavigate(path), where the
host receives the path AFTER the sheet pops and owns the
navigation entirely. The full player wires:
  onNavigate: (path) async {
    await Navigator.of(context).maybePop();
    if (context.mounted) GoRouter.of(context).push(path);
  }
Awaiting the pop guarantees /now-playing is fully gone from the
navigator's page list before the push starts.

Mini player + track rows + everywhere else use the default (no
onNavigate) path that does context.push(path) inline — they're
already inside the ShellRoute, no race possible.

Restored alwaysRefresh: true on artistAlbumsProvider. Dropping it
in the cache-loop fix had a side effect: if drift's cachedAlbums
held only a subset of an artist's albums (user previously visited
just one album by them), the artist detail page rendered that
partial list forever — provider only fetched on empty drift, never
on partial drift. The metadata prefetcher only mass-warms
artistProvider (single row), so re-enabling SWR on artistAlbums
won't recreate the storm.

flutter_client/lib/library/library_providers.dart

@@ -101,6 +101,14 @@ final artistAlbumsProvider =
     isOnline: () async => (await ref
         .read(connectivityProvider.future)
         .timeout(const Duration(seconds: 3), onTimeout: () => true)),
+    // SWR: re-fetch the full album list on every visit. Without this,
+    // a previously-incomplete drift cache (e.g. user had only opened
+    // one album by this artist, so cachedAlbums had just that row)
+    // would render forever as a partial list. The prefetcher only
+    // warms artistProvider (single row), so this provider isn't
+    // mass-instantiated and the storm risk that motivated dropping
+    // alwaysRefresh elsewhere doesn't apply here.
+    alwaysRefresh: true,
     tag: 'artistAlbums($artistId)',
   );
 });

flutter_client/lib/player/now_playing_screen.dart

@@ -400,9 +400,14 @@ class _SecondaryControls extends StatelessWidget {
           // /now-playing lives outside the ShellRoute. Pushing
           // /artists/:id or /albums/:id (both shell-children) on top
           // of it would make go_router try to mount a duplicate
-          // ShellRoute. Pop ourselves first so the destination route
-          // mounts cleanly inside the existing shell.
-          onBeforeNavigate: () => Navigator.of(context).maybePop(),
+          // ShellRoute (the same _debugCheckDuplicatedPageKeys crash
+          // we hit before with /queue). Await our own pop fully
+          // before pushing the destination so go_router never sees
+          // both pages active in the same frame.
+          onNavigate: (path) async {
+            await Navigator.of(context).maybePop();
+            if (context.mounted) GoRouter.of(context).push(path);
+          },
         ),
       ],
     );

flutter_client/lib/shared/widgets/track_actions/track_actions_button.dart

@@ -11,7 +11,7 @@ class TrackActionsButton extends StatelessWidget {
     super.key,
     required this.track,
     this.hideQueueActions = false,
-    this.onBeforeNavigate,
+    this.onNavigate,
   });
 
   final TrackRef track;
@@ -20,10 +20,10 @@ class TrackActionsButton extends StatelessWidget {
   /// screen where the menu's track IS the currently-playing one.
   final bool hideQueueActions;
 
-  /// Forwarded to TrackActionsSheet.onBeforeNavigate. Use to dismiss
-  /// the host route before "Go to album" / "Go to artist" pushes the
-  /// detail screen.
-  final void Function()? onBeforeNavigate;
+  /// Forwarded to TrackActionsSheet.onNavigate. The host receives the
+  /// destination path AFTER the sheet has popped and is responsible
+  /// for navigating to it (typically: pop self first, then push).
+  final Future<void> Function(String path)? onNavigate;
 
   @override
   Widget build(BuildContext context) {
@@ -35,7 +35,7 @@ class TrackActionsButton extends StatelessWidget {
         context,
         track,
         hideQueueActions: hideQueueActions,
-        onBeforeNavigate: onBeforeNavigate,
+        onNavigate: onNavigate,
       ),
     );
   }

flutter_client/lib/shared/widgets/track_actions/track_actions_sheet.dart

@@ -21,25 +21,27 @@ class TrackActionsSheet extends ConsumerWidget {
     super.key,
     required this.track,
     required this.hideQueueActions,
-    this.onBeforeNavigate,
+    this.onNavigate,
   });
 
   final TrackRef track;
   final bool hideQueueActions;
 
-  /// Optional hook invoked just before "Go to album" / "Go to artist"
-  /// pushes the destination route. Lets callers that live OUTSIDE the
-  /// ShellRoute (e.g. the full player at /now-playing) pop themselves
-  /// first, so go_router doesn't try to mount a second ShellRoute on
-  /// top of the active top-level route — the same duplicate-page-key
-  /// failure mode we hit when /queue lived inside the shell.
-  final void Function()? onBeforeNavigate;
+  /// Optional hook for "Go to album" / "Go to artist". Called with
+  /// the destination route path AFTER the sheet has popped. Lets
+  /// callers that live OUTSIDE the ShellRoute (e.g. the full player
+  /// at /now-playing) pop themselves first then push, so go_router
+  /// doesn't try to mount a second ShellRoute on top of the active
+  /// top-level route. When null, the sheet does its own
+  /// context.push, which is correct for surfaces already inside the
+  /// shell (mini player, track rows on detail screens, etc.).
+  final Future<void> Function(String path)? onNavigate;
 
   static Future<void> show(
     BuildContext context,
     TrackRef track, {
     bool hideQueueActions = false,
-    void Function()? onBeforeNavigate,
+    Future<void> Function(String path)? onNavigate,
   }) {
     return showModalBottomSheet<void>(
       context: context,
@@ -47,7 +49,7 @@ class TrackActionsSheet extends ConsumerWidget {
       builder: (_) => TrackActionsSheet(
         track: track,
         hideQueueActions: hideQueueActions,
-        onBeforeNavigate: onBeforeNavigate,
+        onNavigate: onNavigate,
       ),
     );
   }
@@ -152,8 +154,12 @@ class TrackActionsSheet extends ConsumerWidget {
               label: 'Go to album',
               onTap: () {
                 Navigator.pop(context);
-                onBeforeNavigate?.call();
-                context.push('/albums/${track.albumId}');
+                final path = '/albums/${track.albumId}';
+                if (onNavigate != null) {
+                  onNavigate!(path);
+                } else {
+                  context.push(path);
+                }
               },
             ),
             _MenuItem(
@@ -162,8 +168,12 @@ class TrackActionsSheet extends ConsumerWidget {
               label: 'Go to artist',
               onTap: () {
                 Navigator.pop(context);
-                onBeforeNavigate?.call();
-                context.push('/artists/${track.artistId}');
+                final path = '/artists/${track.artistId}';
+                if (onNavigate != null) {
+                  onNavigate!(path);
+                } else {
+                  context.push(path);
+                }
               },
             ),
             const _Divider(),