fix(portal): synchronize destination presentation state

src/AcDream.Core/Physics/PhysicsBody.cs

@@ -200,19 +200,63 @@ public sealed class PhysicsBody
         }
     }
 
+    /// <summary>
+    /// Commits the position and full cell returned by a successful transition.
+    /// Retail <c>CPhysicsObj::SetPositionInternal(CTransition const*)</c>
+    /// (<c>0x00515330</c>) always commits both
+    /// <c>sphere_path.curr_pos.objcell_id</c> and its frame, including EnvCells.
+    /// The ordinary <see cref="Position"/> setter first carries the accepted world
+    /// displacement into the landblock-relative frame; this method then adopts the
+    /// resolver's exact cell identity. Outdoor frames are canonicalized across 24 m
+    /// cells and 192 m landblock boundaries. Indoor frames retain their carried
+    /// landblock-relative origin and adopt the resolved EnvCell id.
+    /// </summary>
+    public void CommitTransitionPosition(uint resolvedCellId, Vector3 worldPosition)
+    {
+        Position = worldPosition;
+
+        if (CellPosition.ObjCellId == 0 || resolvedCellId == 0)
+            return;
+
+        uint cell = resolvedCellId;
+        Vector3 local = CellPosition.Frame.Origin;
+        if ((cell & 0xFFFFu) is >= 1u and <= 0x40u
+            && !LandDefs.AdjustToOutside(ref cell, ref local))
+        {
+            // At the map edge retail's transition does not yield a successful
+            // outside cell. Preserve the carried frame instead of inventing one.
+            return;
+        }
+
+        CellPosition = new Position(
+            cell,
+            new CellFrame(local, CellPosition.Frame.Orientation));
+    }
+
     // Mirror a world-position translation into the cell-relative frame. Velocity is
     // frame-invariant under translation, so the same delta applies to the local origin.
     // AdjustToOutside then recomputes the cell index from the local (intra-landblock 24 m
     // cell crossings) AND wraps + bumps the landblock on a 192 m crossing — the outdoor
     // membership + canonicalization in one call (get_outside_lcoord + lcoord_to_gid +
-    // [0,192) wrap). Idempotent within a cell. Runs only for a SEEDED OUTDOOR cell;
-    // unseeded bodies (ObjCellId==0, e.g. remote entities) and indoor cells are skipped.
+    // [0,192) wrap). Idempotent within a cell. A SEEDED indoor body carries the same
+    // landblock-relative delta but keeps its EnvCell identity until the transition result
+    // commits the exact destination via CommitTransitionPosition. Unseeded bodies are skipped.
     private void SyncCellPositionDelta(Vector3 delta)
     {
         uint cell = CellPosition.ObjCellId;
-        if ((cell & 0xFFFFu) is not (>= 1u and <= 0x40u))
+        if (cell == 0)
             return;
+
         Vector3 local = CellPosition.Frame.Origin + delta;
+
+        if ((cell & 0xFFFFu) is not (>= 1u and <= 0x40u))
+        {
+            CellPosition = new Position(
+                cell,
+                new CellFrame(local, CellPosition.Frame.Orientation));
+            return;
+        }
+
         uint adjusted = cell;
         if (LandDefs.AdjustToOutside(ref adjusted, ref local))
             CellPosition = new Position(adjusted, new CellFrame(local, CellPosition.Frame.Orientation));