feat: add grid/list view toggle to track gallery with hover-reveal art cards

DeepDrftPublic.Client/Pages/TracksView.razor

@@ -7,8 +7,19 @@
     <div class="tracks-view-container">
         @if (ViewModel.Page != null)
         {
+            <div class="tracks-view-header">
+                <MudToggleGroup T="GalleryViewMode" @bind-Value="_viewMode" Class="tracks-view-toggle">
+                    <MudToggleItem Value="GalleryViewMode.Grid">
+                        <MudIcon Icon="@Icons.Material.Filled.ViewModule"/>
+                    </MudToggleItem>
+                    <MudToggleItem Value="GalleryViewMode.List">
+                        <MudIcon Icon="@Icons.Material.Filled.ViewList"/>
+                    </MudToggleItem>
+                </MudToggleGroup>
+            </div>
             <div class="tracks-content">
                 <TracksGallery Tracks="@ViewModel.Page.Items"
+                               ViewMode="@_viewMode"
                                ActiveTrack="@PlayerService.CurrentTrack"
                                IsPlaying="@PlayerService.IsPlaying"
                                IsPaused="@PlayerService.IsPaused"

DeepDrftPublic.Client/Pages/TracksView.razor.cs

@@ -1,4 +1,5 @@
 using DeepDrftModels.DTOs;
+using DeepDrftPublic.Client.Controls;
 using DeepDrftPublic.Client.Services;
 using DeepDrftPublic.Client.ViewModels;
 using Microsoft.AspNetCore.Components;
@@ -17,6 +18,9 @@ public partial class TracksView : ComponentBase, IDisposable
     private IStreamingPlayerService? _subscribedService;
     private PersistingComponentStateSubscription _persistingSubscription;
 
+    // Ephemeral view-mode selection — presentation-only, not persisted across navigation.
+    private GalleryViewMode _viewMode = GalleryViewMode.Grid;
+
     protected override async Task OnInitializedAsync()
     {
         // Carry the prerendered page across the prerender -> interactive (WASM) seam.

DeepDrftPublic.Client/Pages/TracksView.razor.css

@@ -18,3 +18,9 @@
     align-items: center;
     gap: 16px;
 }
+
+.tracks-view-header {
+    display: flex;
+    justify-content: flex-end;
+    padding: 0 0 12px 0;
+}