refactor(runtime): extract local teleport and player mode

Move local teleport, player-mode, animation, shadow, and sealed-dungeon lifetimes out of GameWindow. Make player-mode entry transactional and isolate approach completions by controller lifetime and approach generation so stale callbacks cannot affect replacements.

Co-authored-by: Codex <noreply@openai.com>

tests/AcDream.Core.Tests/Input/AutoEnterPlayerModeTests.cs

@@ -27,6 +27,7 @@ public sealed class AutoEnterPlayerModeTests
         // Defaults TRUE: the world-reveal hold is not under test in the
         // original K.2 cases (see WorldNotReady test for it).
         public bool WorldReady = true;
+        public bool PlayerModeActive;
         public int  EnteredCount;
 
         public PlayerModeAutoEntry Build() =>
@@ -35,7 +36,8 @@ public sealed class AutoEnterPlayerModeTests
                 isPlayerEntityPresent:   () => PlayerEntityPresent,
                 isPlayerControllerReady: () => PlayerControllerReady,
                 isWorldReady:            () => WorldReady,
-                enterPlayerMode:         () => EnteredCount++);
+                enterPlayerMode:         () => EnteredCount++,
+                isPlayerModeActive:      () => PlayerModeActive);
     }
 
     [Fact]
@@ -180,4 +182,25 @@ public sealed class AutoEnterPlayerModeTests
         Assert.True(guard.TryEnter());
         Assert.Equal(1, s.EnteredCount);
     }
+
+    [Fact]
+    public void PortalEntryThatAlreadyActivatedPlayerMode_RetiresArmedGuard()
+    {
+        var s = new State
+        {
+            LiveInWorld = true,
+            PlayerEntityPresent = true,
+            PlayerControllerReady = true,
+        };
+        var guard = s.Build();
+        guard.Arm();
+
+        // F751/player-mode activation occurs before the auto-entry phase in
+        // the update graph. The guard must not rebuild that PortalSpace owner.
+        s.PlayerModeActive = true;
+
+        Assert.False(guard.TryEnter());
+        Assert.False(guard.IsArmed);
+        Assert.Equal(0, s.EnteredCount);
+    }
 }