Consolidate play/pause icon logic into PlaybackIcons mapper and PlayStateIcon component

Add Disabled parameter to PlayStateIcon; forward to MudIconButton;
pass Disabled="!IsLoaded" from PlayerControls to match Stop button parity.

DeepDrftPublic.Client/Controls/AudioPlayerBar/AudioPlayerBar.razor

@@ -13,8 +13,7 @@ else
             <MudPaper Elevation="8" Class="player-surface pa-3">
 
                 <div class="player-layout">
-                    <PlayerTransportZone IsPlaying="IsPlaying"
-                                         IsLoaded="IsLoaded"
+                    <PlayerTransportZone IsLoaded="IsLoaded"
                                          IsLoading="IsLoading"
                                          IsStreaming="IsStreaming"
                                          LoadProgress="LoadProgress"

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

@@ -17,8 +17,6 @@ public partial class AudioPlayerBar : ComponentBase, IAsyncDisposable
     private bool IsLoading => PlayerService?.IsLoading ?? false;
     private bool IsStreaming => PlayerService?.CanStartStreaming ?? false;
     private bool IsStreamingMode => PlayerService?.IsStreamingMode ?? false;
-    private bool IsPlaying => PlayerService?.IsPlaying ?? false;
-    private bool IsPaused => PlayerService?.IsPaused ?? false;
     private double? Duration => PlayerService?.Duration;
     private double Volume => PlayerService?.Volume ?? 0;
     private double LoadProgress => PlayerService?.LoadProgress ?? 0;

DeepDrftPublic.Client/Controls/AudioPlayerBar/PlayerControls.razor

@@ -1,9 +1,11 @@
+@namespace DeepDrftPublic.Client.Controls.AudioPlayerBar
+@using DeepDrftPublic.Client.Controls
+
 <MudStack Row="true" AlignItems="AlignItems.Center" Spacing="2">
-    <MudIconButton Icon="@GetPlayIcon()"
+    <PlayStateIcon Size="Size.Large"
                    Color="Color.Primary"
-                   Size="Size.Large"
-                   OnClick="@TogglePlayPause"
-                   Disabled="!IsLoaded"/>
+                   Disabled="!IsLoaded"
+                   OnToggle="@TogglePlayPause"/>
     <MudIconButton Icon="@Icons.Material.Filled.Stop"
                    Color="Color.Primary"
                    Size="Size.Large"

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

@@ -1,16 +1,10 @@
-using Microsoft.AspNetCore.Components;
-using MudBlazor;
+using Microsoft.AspNetCore.Components;
 
 namespace DeepDrftPublic.Client.Controls.AudioPlayerBar;
 
 public partial class PlayerControls : ComponentBase
 {
-    [Parameter] public required bool IsPlaying { get; set; }
     [Parameter] public required bool IsLoaded { get; set; }
     [Parameter] public required EventCallback TogglePlayPause { get; set; }
     [Parameter] public required EventCallback Stop { get; set; }
-    private string GetPlayIcon()
-    {
-        return IsPlaying ? Icons.Material.Filled.Pause : Icons.Material.Filled.PlayArrow;
-    }
-}
+}

DeepDrftPublic.Client/Controls/AudioPlayerBar/PlayerTransportZone.razor

@@ -1,8 +1,7 @@
 @namespace DeepDrftPublic.Client.Controls.AudioPlayerBar
 
 <MudStack Row="true" AlignItems="AlignItems.Center" Spacing="1" Class="@Class">
-    <PlayerControls IsPlaying="IsPlaying"
-                    IsLoaded="IsLoaded"
+    <PlayerControls IsLoaded="IsLoaded"
                     TogglePlayPause="TogglePlayPause"
                     Stop="Stop"/>
     @if (IsLoading && !IsStreaming)

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

@@ -4,7 +4,6 @@ namespace DeepDrftPublic.Client.Controls.AudioPlayerBar;
 
 public partial class PlayerTransportZone : ComponentBase
 {
-    [Parameter] public bool IsPlaying { get; set; }
     [Parameter] public bool IsLoaded { get; set; }
     [Parameter] public bool IsLoading { get; set; }
     [Parameter] public bool IsStreaming { get; set; }