fix(portal): synchronize destination presentation state

src/AcDream.Core/Physics/ShadowObjectRegistry.cs

@@ -29,6 +29,10 @@ public sealed class ShadowObjectRegistry
     private readonly Dictionary<uint, List<ShadowEntry>> _cells = new();
     private readonly Dictionary<uint, List<uint>> _entityToCells = new(); // for deregistration
     private readonly HashSet<uint> _suspendedEntities = new();
+    // Rows withdrawn because a touched landblock streamed out. The owner may
+    // be seeded in an adjacent still-resident landblock, so its remaining rows
+    // cannot by themselves tell RefloodLandblock that this prefix needs repair.
+    private readonly Dictionary<uint, HashSet<uint>> _withdrawnPrefixesByOwner = new();
 
     /// <summary>
     /// A6.P4 door fix (2026-05-24): per-entity original shape list, used by
@@ -367,7 +371,7 @@ public sealed class ShadowObjectRegistry
     public void RefloodLandblock(uint landblockId)
     {
         uint lbPrefix = landblockId & 0xFFFF0000u;
-        var toReflood = new List<uint>();
+        var toReflood = new HashSet<uint>();
 
         foreach (var kvp in _entityReg)
         {
@@ -390,11 +394,17 @@ public sealed class ShadowObjectRegistry
                     }
                 }
             }
+            if (_withdrawnPrefixesByOwner.TryGetValue(kvp.Key, out var prefixes)
+                && prefixes.Contains(lbPrefix))
+            {
+                toReflood.Add(kvp.Key);
+            }
         }
 
         foreach (uint entityId in toReflood)
         {
             var reg = _entityReg[entityId];
+            _withdrawnPrefixesByOwner.TryGetValue(entityId, out var withdrawnBeforeReflood);
             if (reg.IsMultiPart && _entityShapes.TryGetValue(entityId, out var shapes))
             {
                 RegisterMultiPart(entityId, reg.EntityWorldPos, reg.EntityWorldRot, shapes,
@@ -408,6 +418,22 @@ public sealed class ShadowObjectRegistry
                          reg.CollisionType, reg.CylHeight, reg.Scale,
                          reg.State, reg.Flags, reg.SeedCellId, reg.IsStatic);
             }
+
+            // Register is also the authoritative movement/replacement API and
+            // therefore clears obsolete markers. Only this streaming reflood
+            // operation preserves the still-missing prefixes across replacement.
+            if (withdrawnBeforeReflood is not null)
+                _withdrawnPrefixesByOwner[entityId] = withdrawnBeforeReflood;
+
+            if (_entityToCells.TryGetValue(entityId, out var refreshedCells)
+                && refreshedCells.Exists(cell =>
+                    (cell & 0xFFFF0000u) == lbPrefix)
+                && _withdrawnPrefixesByOwner.TryGetValue(entityId, out var withdrawn))
+            {
+                withdrawn.Remove(lbPrefix);
+                if (withdrawn.Count == 0)
+                    _withdrawnPrefixesByOwner.Remove(entityId);
+            }
         }
     }
 
@@ -475,6 +501,29 @@ public sealed class ShadowObjectRegistry
         _entityShapes.Remove(entityId);
         _entityReg.Remove(entityId);
         _suspendedEntities.Remove(entityId);
+        _withdrawnPrefixesByOwner.Remove(entityId);
+    }
+
+    /// <summary>
+    /// Logically tear down every static object owned by a landblock, including
+    /// shadow rows flooded into adjacent landblocks. Dynamic/server-live owners
+    /// are deliberately retained for spatial reflood after streaming changes.
+    /// </summary>
+    public void DeregisterStaticOwnersForLandblock(uint landblockId)
+    {
+        uint prefix = landblockId & 0xFFFF0000u;
+        var owners = new List<uint>();
+        foreach (var (entityId, registration) in _entityReg)
+        {
+            if (registration.IsStatic
+                && (registration.SeedCellId & 0xFFFF0000u) == prefix)
+            {
+                owners.Add(entityId);
+            }
+        }
+
+        foreach (uint entityId in owners)
+            Deregister(entityId);
     }
 
     /// <summary>
@@ -491,6 +540,18 @@ public sealed class ShadowObjectRegistry
         uint lbPrefix = landblockId & 0xFFFF0000u;
         var toRemove = new List<uint>();
 
+        foreach (var (entityId, cells) in _entityToCells)
+        {
+            if (!cells.Exists(cell => (cell & 0xFFFF0000u) == lbPrefix))
+                continue;
+            if (!_withdrawnPrefixesByOwner.TryGetValue(entityId, out var withdrawn))
+            {
+                withdrawn = new HashSet<uint>();
+                _withdrawnPrefixesByOwner[entityId] = withdrawn;
+            }
+            withdrawn.Add(lbPrefix);
+        }
+
         foreach (var kvp in _cells)
         {
             if ((kvp.Key & 0xFFFF0000u) == lbPrefix)
@@ -520,6 +581,7 @@ public sealed class ShadowObjectRegistry
                 _entityShapes.Remove(eid);
                 _entityReg.Remove(eid);
                 _suspendedEntities.Remove(eid);
+                _withdrawnPrefixesByOwner.Remove(eid);
             }
         }
     }
@@ -549,6 +611,18 @@ public sealed class ShadowObjectRegistry
     /// </summary>
     public int RetainedRegistrationCount => _entityReg.Count;
 
+    /// <summary>Number of owner/prefix repair markers awaiting a future reflood.</summary>
+    public int WithdrawnPrefixMarkerCount
+    {
+        get
+        {
+            int count = 0;
+            foreach (var prefixes in _withdrawnPrefixesByOwner.Values)
+                count += prefixes.Count;
+            return count;
+        }
+    }
+
     /// <summary>Suspended logical registrations awaiting spatial re-entry.</summary>
     public int SuspendedRegistrationCount => _suspendedEntities.Count;