feat(core/slice-1): TeleportAnimSequencer — define enums, record, event types

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/AcDream.Core.Tests/World/TeleportAnimSequencerTests.cs

@@ -0,0 +1,43 @@
+using AcDream.Core.World;
+using Xunit;
+
+namespace AcDream.Core.Tests.World;
+
+public sealed class TeleportAnimSequencerTests
+{
+    // --- Task 1.1: type presence ---
+
+    [Fact]
+    public void Enums_HaveExpectedValues()
+    {
+        Assert.Equal(0, (int)TeleportAnimState.Off);
+        Assert.Equal(1, (int)TeleportAnimState.WorldFadeOut);
+        Assert.Equal(2, (int)TeleportAnimState.TunnelFadeIn);
+        Assert.Equal(3, (int)TeleportAnimState.Tunnel);
+        Assert.Equal(4, (int)TeleportAnimState.TunnelContinue);
+        Assert.Equal(5, (int)TeleportAnimState.TunnelFadeOut);
+        Assert.Equal(6, (int)TeleportAnimState.WorldFadeIn);
+
+        _ = TeleportEntryKind.Portal;
+        _ = TeleportEntryKind.Login;
+        _ = TeleportEntryKind.Death;
+        _ = TeleportEntryKind.Logout;
+
+        _ = TeleportAnimEvent.PlayEnterSound;
+        _ = TeleportAnimEvent.PlayExitSound;
+        _ = TeleportAnimEvent.Place;
+        _ = TeleportAnimEvent.FireLoginComplete;
+        _ = TeleportAnimEvent.EnterTunnel;
+    }
+
+    [Fact]
+    public void Snapshot_DefaultsAreOff_ClearAlpha()
+    {
+        var snap = new TeleportAnimSnapshot(
+            TeleportAnimState.Off, FadeAlpha: 0f, ShowTunnel: false, ShowPleaseWait: false);
+        Assert.Equal(TeleportAnimState.Off, snap.State);
+        Assert.Equal(0f, snap.FadeAlpha);
+        Assert.False(snap.ShowTunnel);
+        Assert.False(snap.ShowPleaseWait);
+    }
+}