fix(audio): keep unavailable world slots quiescent

Construct the retail-sized world voice ledger independently of OpenAL device availability so world reveal suspension is a safe no-op on machines without an audio backend.

Co-authored-by: Erik Nilsson <erikn@users.noreply.github.com>

tests/AcDream.App.Tests/Audio/OpenAlResourceLifetimeTests.cs

@@ -89,6 +89,21 @@ public sealed class OpenAlResourceLifetimeTests
         Assert.Equal(1, api.CloseDeviceCalls);
     }
 
+    [Fact]
+    public void UnavailableEngineWorldQuiescenceRemainsASafeNoOp()
+    {
+        var api = new RecordingApi { ContextResult = 0 };
+        var engine = new OpenAlAudioEngine(new Factory(api));
+
+        engine.SuspendWorldAudio();
+        engine.StopAllForOwner(0x50000001u);
+        engine.ResumeWorldAudio();
+
+        Assert.False(engine.IsAvailable);
+        Assert.True(engine.IsDisposalComplete);
+        Assert.Empty(api.GeneratedSources);
+    }
+
     private sealed class Factory(IOpenAlResourceApi api) : IOpenAlResourceApiFactory
     {
         public IOpenAlResourceApi Create() => api;