Merge dev into p10-w4-popover-knobs (integrate concurrent Phase 11 scaffold changes)

# Conflicts:
#	DeepDrftPublic.Client/Controls/ReleaseDetailScaffold.razor.cs

DeepDrftPublic.Client/Controls/AudioPlayerBar/AudioPlayerBar.razor

@@ -21,6 +21,10 @@ else
                                          Fixed="Fixed"
                                          TogglePlayPause="@TogglePlayPause"
                                          Stop="@Stop"
+                                         HasNext="HasNext"
+                                         HasPrevious="HasPrevious"
+                                         SkipNext="@SkipNext"
+                                         SkipPrevious="@SkipPrevious"
                                          Class="transport-zone"/>
 
                     <VolumeZone Volume="@Volume" VolumeChanged="@OnVolumeChange"/>

DeepDrftPublic.Client/Controls/AudioPlayerBar/AudioPlayerBar.razor.cs

@@ -9,6 +9,7 @@ namespace DeepDrftPublic.Client.Controls.AudioPlayerBar;
 public partial class AudioPlayerBar : ComponentBase, IAsyncDisposable
 {
     [CascadingParameter] public IStreamingPlayerService? PlayerService { get; set; }
+    [CascadingParameter] public IQueueService? QueueService { get; set; }
     [Parameter] public bool Fixed { get; set; } = false;
 
     [Parameter] public EventCallback<bool> OnMinimized { get; set; }
@@ -19,6 +20,7 @@ public partial class AudioPlayerBar : ComponentBase, IAsyncDisposable
     private bool _isSeeking = false;
     private double _seekPosition = 0;
     private IStreamingPlayerService? _subscribedService;
+    private IQueueService? _subscribedQueue;
 
     // Spacer-height bridge: the expanded dock is position:fixed, so MainLayout's
     // spacer reserves its space. We mirror this element's live height into a CSS
@@ -48,6 +50,11 @@ public partial class AudioPlayerBar : ComponentBase, IAsyncDisposable
     private double LoadProgress => PlayerService?.LoadProgress ?? 0;
     private string? ErrorMessage => PlayerService?.ErrorMessage;
 
+    // Skip affordances reflect live queue state. With no queue (null) or an empty queue both are
+    // false, so the buttons sit disabled and the bar behaves exactly as it did before the queue.
+    private bool HasNext => QueueService?.HasNext ?? false;
+    private bool HasPrevious => QueueService?.HasPrevious ?? false;
+
     /// <summary>
     /// Display time - shows seek position while dragging, otherwise current playback time.
     /// </summary>
@@ -76,10 +83,35 @@ public partial class AudioPlayerBar : ComponentBase, IAsyncDisposable
             PlayerService.StateChanged += OnPlayerStateChanged;
             _subscribedService = PlayerService;
         }
+
+        // The queue cascade is also IsFixed, so re-render the skip affordances off its own
+        // change signal — same posture as the player StateChanged subscription above.
+        if (QueueService != null && !ReferenceEquals(QueueService, _subscribedQueue))
+        {
+            if (_subscribedQueue != null)
+                _subscribedQueue.QueueChanged -= OnQueueChanged;
+
+            QueueService.QueueChanged += OnQueueChanged;
+            _subscribedQueue = QueueService;
+        }
     }
 
     private void OnPlayerStateChanged() => InvokeAsync(StateHasChanged);
 
+    private void OnQueueChanged() => InvokeAsync(StateHasChanged);
+
+    private async Task SkipNext()
+    {
+        if (QueueService == null) return;
+        await QueueService.Next();
+    }
+
+    private async Task SkipPrevious()
+    {
+        if (QueueService == null) return;
+        await QueueService.Previous();
+    }
+
     protected override async Task OnAfterRenderAsync(bool firstRender)
     {
         // Only the docked, expanded shape needs a spacer: the Fixed embed is

DeepDrftPublic.Client/Controls/AudioPlayerBar/PlayerControls.razor

@@ -2,12 +2,25 @@
 @using DeepDrftPublic.Client.Controls
 
 <MudStack Row="true" AlignItems="AlignItems.Center" Spacing="2">
+    @if (!Fixed)
+    {
+        <MudIconButton Icon="@Icons.Material.Filled.SkipPrevious"
+                       Color="Color.Primary"
+                       Size="Size.Large"
+                       OnClick="@SkipPrevious"
+                       Disabled="!HasPrevious"/>
+    }
     <PlayStateIcon Size="Size.Large"
                    Color="Color.Primary"
                    Disabled="!CanPlay"
                    OnToggle="@TogglePlayPause"/>
     @if (!Fixed)
     {
+        <MudIconButton Icon="@Icons.Material.Filled.SkipNext"
+                       Color="Color.Primary"
+                       Size="Size.Large"
+                       OnClick="@SkipNext"
+                       Disabled="!HasNext"/>
         <MudIconButton Icon="@Icons.Material.Filled.Stop"
                        Color="Color.Primary"
                        Size="Size.Large"

DeepDrftPublic.Client/Controls/AudioPlayerBar/PlayerControls.razor.cs

@@ -16,4 +16,13 @@ public partial class PlayerControls : ComponentBase
     [Parameter] public bool Fixed { get; set; } = false;
     [Parameter] public required EventCallback TogglePlayPause { get; set; }
     [Parameter] public required EventCallback Stop { get; set; }
+
+    /// <summary>Whether the queue has a track to skip forward to. Drives the skip-next affordance.</summary>
+    [Parameter] public bool HasNext { get; set; }
+
+    /// <summary>Whether the queue has a track to step back to. Drives the skip-previous affordance.</summary>
+    [Parameter] public bool HasPrevious { get; set; }
+
+    [Parameter] public EventCallback SkipNext { get; set; }
+    [Parameter] public EventCallback SkipPrevious { get; set; }
 }

DeepDrftPublic.Client/Controls/AudioPlayerBar/PlayerTransportZone.razor

@@ -6,7 +6,11 @@
                         CanPlay="CanPlay"
                         Fixed="Fixed"
                         TogglePlayPause="TogglePlayPause"
-                        Stop="Stop"/>
+                        Stop="Stop"
+                        HasNext="HasNext"
+                        HasPrevious="HasPrevious"
+                        SkipNext="SkipNext"
+                        SkipPrevious="SkipPrevious"/>
         @if (IsLoading && !IsStreaming)
         {
             <MudProgressCircular Color="Color.Tertiary"

DeepDrftPublic.Client/Controls/AudioPlayerBar/PlayerTransportZone.razor.cs

@@ -14,5 +14,9 @@ public partial class PlayerTransportZone : ComponentBase
     [Parameter] public bool Fixed { get; set; } = false;
     [Parameter] public EventCallback TogglePlayPause { get; set; }
     [Parameter] public EventCallback Stop { get; set; }
+    [Parameter] public bool HasNext { get; set; }
+    [Parameter] public bool HasPrevious { get; set; }
+    [Parameter] public EventCallback SkipNext { get; set; }
+    [Parameter] public EventCallback SkipPrevious { get; set; }
     [Parameter] public string? Class { get; set; }
 }

DeepDrftPublic.Client/Controls/AudioPlayerProvider.razor

@@ -3,5 +3,7 @@
    If instance swapping at runtime is ever needed, change IsFixed to false (adds subscription
    overhead on every parent re-render, but allows children to see the new reference). *@
 <CascadingValue Value="@(_audioPlayerService)" IsFixed="true">
-    @ChildContent
+    <CascadingValue Value="@(_queueService)" IsFixed="true">
+        @ChildContent
+    </CascadingValue>
 </CascadingValue>

DeepDrftPublic.Client/Controls/AudioPlayerProvider.razor.cs

@@ -12,6 +12,7 @@ public partial class AudioPlayerProvider : ComponentBase, IAsyncDisposable
     [Inject] public required ILogger<StreamingAudioPlayerService> Logger { get; set; }
 
     private IStreamingPlayerService? _audioPlayerService;
+    private QueueService? _queueService;
 
     [Parameter] public RenderFragment? ChildContent { get; set; }
 
@@ -29,6 +30,13 @@ public partial class AudioPlayerProvider : ComponentBase, IAsyncDisposable
         // Children must not wrap or replace this callback.
         _audioPlayerService.OnStateChanged = new EventCallback(this, () => InvokeAsync(StateHasChanged));
         // OnTrackSelected will be set by individual child components that need it
+
+        // The queue orchestrates above the single-slot player. The player is not DI-registered
+        // (constructed here), so the queue binds to it via Attach rather than constructor injection —
+        // no construction cycle, no IServiceProvider. Cascaded alongside the player so the bar and a
+        // future up-next panel both read it.
+        _queueService = new QueueService();
+        _queueService.Attach(_audioPlayerService);
     }
 
     /// <summary>
@@ -38,6 +46,11 @@ public partial class AudioPlayerProvider : ComponentBase, IAsyncDisposable
     /// </summary>
     public async ValueTask DisposeAsync()
     {
+        // Dispose the queue first so it unsubscribes from the player's TrackEnded before the
+        // player tears down.
+        _queueService?.Dispose();
+        _queueService = null;
+
         if (_audioPlayerService is IAsyncDisposable disposable)
         {
             await disposable.DisposeAsync();

DeepDrftPublic.Client/Controls/ReleaseDetailScaffold.razor

@@ -19,20 +19,30 @@
 
     @TopContent
 
-    <MudStack Row AlignItems="AlignItems.Start" Justify="Justify.SpaceBetween" Style="margin: 2rem 0 1.5rem;">
-        <div class="deepdrft-track-detail-masthead">
-            <MudText Typo="Typo.h3">@Title</MudText>
-            <MudText Typo="Typo.h6" Color="Color.Primary">@Artist</MudText>
-        </div>
+    @* The header region. A composer that wants the default masthead+play row supplies nothing; one
+       that needs a different arrangement (e.g. the Cut album's left-meta / right-cover split) supplies
+       its own Header fragment. Layout variance rides this slot, never a boolean flag (Phase 9 §5.3). *@
+    @if (Header is not null)
+    {
+        @Header
+    }
+    else
+    {
+        <MudStack Row AlignItems="AlignItems.Start" Justify="Justify.SpaceBetween" Style="margin: 2rem 0 1.5rem;">
+            <div class="deepdrft-track-detail-masthead">
+                <MudText Typo="Typo.h3">@Title</MudText>
+                <MudText Typo="Typo.h6" Color="Color.Primary">@Artist</MudText>
+            </div>
 
-        @* Play only makes sense once a playable track is resolved. *@
-        @if (Track is not null)
-        {
-            <MudStack Row AlignItems="AlignItems.Center" Spacing="1">
-                <PlayStateIcon Track="@Track" Size="Size.Large" Color="Color.Secondary" OnToggle="@PlayTrack" />
-            </MudStack>
-        }
-    </MudStack>
+            @* Play only makes sense once a playable track is resolved. *@
+            @if (Track is not null)
+            {
+                <MudStack Row AlignItems="AlignItems.Center" Spacing="1">
+                    <PlayStateIcon Track="@Track" Size="Size.Large" Color="Color.Secondary" OnToggle="@PlayTrack" />
+                </MudStack>
+            }
+        </MudStack>
+    }
 
     @Hero
 
@@ -44,7 +54,12 @@
         </div>
     }
 
-    @if (Track is not null)
+    @* Multi-track body region (the Cut album's track list). Single-track media leave it null. *@
+    @BodyContent
+
+    @* The default share row is bound to the single resolved track. A composer that owns its own share
+       affordance (the Cut header carries Play + Share inline) suppresses it via ShowShareRow. *@
+    @if (Track is not null && ShowShareRow)
     {
         <div class="deepdrft-share-row">
             <SharePopover EntryKey="@Track.EntryKey" />

DeepDrftPublic.Client/Controls/ReleaseDetailScaffold.razor.cs

@@ -38,9 +38,24 @@ public partial class ReleaseDetailScaffold : ComponentBase
     /// </summary>
     [Parameter] public RenderFragment? TopRightAction { get; set; }
 
+    /// <summary>
+    /// Optional replacement for the header region (masthead + play affordance). When null, the
+    /// scaffold renders its default masthead+play row wired to <see cref="PlayTrack"/>. A composer
+    /// that needs a different header arrangement (e.g. the Cut album's left-meta / right-cover split
+    /// with its own Play/Share buttons) supplies this — layout variance rides the slot, never a
+    /// boolean flag (Phase 9 §5.3).
+    /// </summary>
+    [Parameter] public RenderFragment? Header { get; set; }
+
     /// <summary>Medium-specific hero visual (cover art, hero image, or waveform background).</summary>
     [Parameter] public RenderFragment? Hero { get; set; }
 
+    /// <summary>
+    /// Optional body region rendered below the meta block — the Cut album's multi-track listing.
+    /// Single-track media leave it null.
+    /// </summary>
+    [Parameter] public RenderFragment? BodyContent { get; set; }
+
     /// <summary>Optional medium-specific metadata block, rendered under a divider when present.</summary>
     [Parameter] public RenderFragment? MetaContent { get; set; }
 
@@ -51,6 +66,13 @@ public partial class ReleaseDetailScaffold : ComponentBase
     /// </summary>
     [Parameter] public bool ShowMeta { get; set; } = true;
 
+    /// <summary>
+    /// Gate for the default track-keyed share row at the foot of the scaffold. A composer that owns
+    /// its own share affordance (the Cut header carries Play + Share inline) sets this false to
+    /// suppress the duplicate. Defaults to shown.
+    /// </summary>
+    [Parameter] public bool ShowShareRow { get; set; } = true;
+
     private async Task PlayTrack()
     {
         if (Track is null || PlayerService is null) return;