fix(physics): keep remote placement and targeting in one world frame

CreateObject positions are landblock-local, but Runtime first-entry previously submitted remotes with a zero world offset. Runtime now owns the accepted local-player world-frame center and converts remote placements before SetPosition. The local physics host also publishes body.Position rather than CellPosition's landblock-local origin, so TargetManager no longer directs monsters toward a phantom player position. User gate: monster/static placement, chase, and attacks accepted outside Tusker Barracks.

src/AcDream.Runtime/Entities/RuntimeEntityObjectLifetime.cs

@@ -556,6 +556,18 @@ public sealed class RuntimeEntityObjectLifetime : IDisposable
         Func<RuntimeEntityRecord, Exception?>? retirePriorProjection)
     {
         EnsureNotDisposed();
+        if (beginInitialResidence
+            && isLocalPlayer
+            && (incoming.Physics?.Position ?? incoming.Position)
+                is { LandblockId: not 0u } initialPlayerPosition)
+        {
+            // The accepted local Create establishes the shared world frame
+            // before any remote first-entry conductor converts its authored
+            // landblock-local coordinates.
+            Physics.ObserveLocalWorldFrame(
+                initialPlayerPosition.LandblockId,
+                teleportAdvanced: false);
+        }
         if (_sessionClearInProgress)
         {
             throw new InvalidOperationException(
@@ -1508,6 +1520,14 @@ public sealed class RuntimeEntityObjectLifetime : IDisposable
             if (!deferredKnown)
                 return false;
 
+            if (isLocalPlayer
+                && disposition is not PositionTimestampDisposition.Rejected)
+            {
+                Physics.ObserveLocalWorldFrame(
+                    update.Position.LandblockId,
+                    timestamps.TeleportAdvanced);
+            }
+
             if (disposition is PositionTimestampDisposition.Rejected
                 && !timestampMutation)
             {
@@ -1556,6 +1576,14 @@ public sealed class RuntimeEntityObjectLifetime : IDisposable
             return known;
         }
 
+        if (isLocalPlayer
+            && disposition is not PositionTimestampDisposition.Rejected)
+        {
+            Physics.ObserveLocalWorldFrame(
+                update.Position.LandblockId,
+                timestamps.TeleportAdvanced);
+        }
+
         bool acceptedPosition =
             disposition is not PositionTimestampDisposition.Rejected;
         if (disposition is PositionTimestampDisposition.Apply)

src/AcDream.Runtime/Entities/RuntimeRemoteFirstEntryState.cs

@@ -346,7 +346,8 @@ internal sealed class RuntimeRemoteFirstEntryState
                     lease.Route.SetPositionFlags,
                     collisionSource,
                     gameTime,
-                    out RuntimeSetPositionCommand command);
+                    out RuntimeSetPositionCommand command,
+                    resolveWorldOffsetFromRuntimeFrame: true);
             if (moverStatus
                 == RuntimeSetPositionMoverPreparationStatus.RetrySetupUnavailable)
             {