fix: complete retail parity stability pass

tests/AcDream.Core.Tests/Audio/DatSoundCacheTests.cs

@@ -142,11 +142,6 @@ public sealed class DatSoundCacheTests
     [Trait("Status", "KnownFailure")]
     public void GetWave_ConcurrentSameId_PublishesOneCanonicalWaveAndDecodesOnce()
     {
-        // #321: a stale caller can pass the resident-cache check, pause, and
-        // reach _inflight after the winning caller has decoded, admitted, and
-        // removed its Lazy. That second Lazy performs a duplicate decode.
-        // R3 preserves this product defect as an explicit known-failure lane;
-        // fixing the cache algorithm is outside the test-only cleanup scope.
         var dats = new FakeDatObjectSource();
         dats.AddWave(1, MakePcmWave(1, dataBytes: 1000));
         var cache = new DatSoundCache(dats, maxWaveBytes: 10_000);
@@ -161,6 +156,55 @@ public sealed class DatSoundCacheTests
         Assert.Equal(1, dats.GetCallCount(1));
     }
 
+    [Fact]
+    public async Task GetWave_StaleMissCannotDecodeAgainAfterWinnerPublishes()
+    {
+        using var winnerDecodeEntered = new ManualResetEventSlim();
+        using var releaseWinnerDecode = new ManualResetEventSlim();
+        using var staleMissParked = new ManualResetEventSlim();
+        using var releaseStaleMiss = new ManualResetEventSlim();
+
+        var dats = new FakeDatObjectSource
+        {
+            BeforeWaveGet = _ =>
+            {
+                winnerDecodeEntered.Set();
+                if (!releaseWinnerDecode.Wait(TimeSpan.FromSeconds(5)))
+                    throw new TimeoutException("winner decode was never released");
+            },
+        };
+        dats.AddWave(1, MakePcmWave(1, dataBytes: 1000));
+
+        int initialMissOrdinal = 0;
+        var cache = new DatSoundCache(
+            dats,
+            maxWaveBytes: 10_000,
+            afterInitialWaveMiss: _ =>
+            {
+                if (Interlocked.Increment(ref initialMissOrdinal) != 2)
+                    return;
+
+                staleMissParked.Set();
+                if (!releaseStaleMiss.Wait(TimeSpan.FromSeconds(5)))
+                    throw new TimeoutException("stale miss was never released");
+            });
+
+        Task<WaveData?> winner = Task.Run(() => cache.GetWave(1));
+        Assert.True(winnerDecodeEntered.Wait(TimeSpan.FromSeconds(5)));
+
+        Task<WaveData?> stale = Task.Run(() => cache.GetWave(1));
+        Assert.True(staleMissParked.Wait(TimeSpan.FromSeconds(5)));
+
+        releaseWinnerDecode.Set();
+        WaveData? canonical = await winner;
+        releaseStaleMiss.Set();
+        WaveData? recovered = await stale;
+
+        Assert.NotNull(canonical);
+        Assert.Same(canonical, recovered);
+        Assert.Equal(1, dats.GetCallCount(1));
+    }
+
     [Fact]
     public void GetWave_ConcurrentMissingId_NeverThrowsAndAllReturnNull()
     {
@@ -214,6 +258,8 @@ public sealed class DatSoundCacheTests
 
         public void AddWave(uint id, Wave wave) => _waves[id] = wave;
 
+        public Action<uint>? BeforeWaveGet { get; init; }
+
         public int GetCallCount(uint id)
         {
             lock (_gate)
@@ -225,6 +271,7 @@ public sealed class DatSoundCacheTests
         {
             if (typeof(T) == typeof(Wave))
             {
+                BeforeWaveGet?.Invoke(fileId);
                 lock (_gate)
                 {
                     _callCounts.TryGetValue(fileId, out int count);

tests/AcDream.Core.Tests/Chat/ChatLogTests.cs

@@ -125,7 +125,9 @@ public sealed class ChatLogTests
     {
         var log = new ChatLog();
         log.OnPlayerKilled("Caith was killed by a Drudge.",
-            victimGuid: 0x12345678u, killerGuid: 0x90ABCDEFu);
+            victimGuid: 0x12345678u,
+            killerGuid: 0x90ABCDEFu,
+            localPlayerGuid: 0x11111111u);
         var e = log.Snapshot()[0];
         Assert.Equal(ChatKind.System, e.Kind);
         Assert.Equal("Caith was killed by a Drudge.", e.Text);
@@ -133,6 +135,25 @@ public sealed class ChatLogTests
         Assert.Equal(0x90ABCDEFu, e.ChannelId);   // killer guid stashed here
     }
 
+    [Theory]
+    [InlineData(0x12345678u)]
+    [InlineData(0x90ABCDEFu)]
+    public void OnPlayerKilled_SuppressesVictimAndKiller(uint localPlayerGuid)
+    {
+        var log = new ChatLog();
+        int appended = 0;
+        log.EntryAppended += _ => appended++;
+
+        log.OnPlayerKilled(
+            "Caith was killed by a Drudge.",
+            victimGuid: 0x12345678u,
+            killerGuid: 0x90ABCDEFu,
+            localPlayerGuid);
+
+        Assert.Empty(log.Snapshot());
+        Assert.Equal(0, appended);
+    }
+
     // OnWeenieError-specific tests (plain code, interpolation, silent
     // client-control statuses) were removed here — REJECT-review rework
     // (SHOULD-FIX 3, docs/research/2026-08-09-ch2-review-findings.md)
@@ -230,7 +251,11 @@ public sealed class ChatLogTests
     public void OnPlayerKilled_LogTextType_IsDefault()
     {
         var log = new ChatLog();
-        log.OnPlayerKilled("Caith was killed by a Drudge.", 0x1u, 0x2u);
+        log.OnPlayerKilled(
+            "Caith was killed by a Drudge.",
+            0x1u,
+            0x2u,
+            localPlayerGuid: 0x3u);
         Assert.Equal(0x00u, log.Snapshot()[0].LogTextType);
     }
 

tests/AcDream.Core.Tests/Physics/MotionSequenceGateTests.cs

@@ -265,15 +265,28 @@ public class PhysicsTimestampGateTests
     }
 
     [Fact]
-    public void FreshForceWithNewerTeleport_UsesNormalPositionPath()
+    public void FreshForceWithNewerTeleport_UsesForcePathWithoutConsumingTeleport()
     {
         var gate = new PhysicsTimestampGate();
         gate.SeedForCreateObject(10, 0, 0, 0, 20, 0, 30, 0, 1);
 
-        Assert.Equal(PositionTimestampDisposition.Apply,
+        Assert.Equal(PositionTimestampDisposition.ForcePosition,
             gate.TryAcceptPositionEvent(1, 11, 21, 31, isLocalPlayer: true));
         Assert.Equal((ushort)11, gate.PositionTimestamp);
-        Assert.Equal((ushort)21, gate.TeleportTimestamp);
+        Assert.Equal((ushort)20, gate.TeleportTimestamp);
+        Assert.Equal((ushort)31, gate.ForcePositionTimestamp);
+    }
+
+    [Fact]
+    public void FreshForceWithWrappedNewerTeleport_UsesForcePathWithoutConsumingTeleport()
+    {
+        var gate = new PhysicsTimestampGate();
+        gate.SeedForCreateObject(10, 0, 0, 0, ushort.MaxValue, 0, 30, 0, 1);
+
+        Assert.Equal(PositionTimestampDisposition.ForcePosition,
+            gate.TryAcceptPositionEvent(1, 11, 0, 31, isLocalPlayer: true));
+        Assert.Equal((ushort)11, gate.PositionTimestamp);
+        Assert.Equal(ushort.MaxValue, gate.TeleportTimestamp);
         Assert.Equal((ushort)31, gate.ForcePositionTimestamp);
     }
 

tests/AcDream.Core.Tests/Physics/RetailAnimationCyclePlaybackTests.cs

@@ -76,13 +76,22 @@ public sealed class RetailAnimationCyclePlaybackTests
     }
 
     [Fact]
-    public void Advance_NonPositiveFramerateOrElapsed_ReturnsCurrFrameUnchanged()
+    public void Advance_ZeroFramerateOrNonPositiveElapsed_ReturnsCurrFrameUnchanged()
     {
         Assert.Equal(3f, RetailAnimationCyclePlayback.Advance(3f, 0, 29, framerate: 0f, elapsedSeconds: 1f));
         Assert.Equal(3f, RetailAnimationCyclePlayback.Advance(3f, 0, 29, framerate: 30f, elapsedSeconds: 0f));
         Assert.Equal(3f, RetailAnimationCyclePlayback.Advance(3f, 0, 29, framerate: 30f, elapsedSeconds: -1f));
     }
 
+    [Fact]
+    public void Advance_NegativeFramerate_MovesBackwardAndClampsAtLowFrame()
+    {
+        Assert.Equal(3f, RetailAnimationCyclePlayback.Advance(
+            5f, lowFrame: 0, highFrame: 29, framerate: -2f, elapsedSeconds: 1f));
+        Assert.Equal(0f, RetailAnimationCyclePlayback.Advance(
+            1f, lowFrame: 0, highFrame: 29, framerate: -2f, elapsedSeconds: 1f));
+    }
+
     [Fact]
     public void TryInterpolatePart_ExactFrame_ReturnsThatFramesPose()
     {