feat(net): port retail physics spawn and event timestamps

Parse the complete PhysicsDesc plus F754/F755 packets, correct every PhysicsState bit, and gate all nine retail update channels with generation-safe immutable snapshots. Preserve ForcePosition, teleport, placement, velocity, parent, pickup, delete, and same-generation CreateObject ordering from the named client.

Separate accepted logical lifecycle notifications from retained UI qualities, make GUID replacement and session reset clear every projection exactly once, and add packet, wraparound, malformed-input, parent FIFO, canonical-position, reconnect, and GUID-reuse conformance coverage.

Co-Authored-By: Codex <noreply@openai.com>

tests/AcDream.App.Tests/UI/Layout/InventoryControllerTests.cs

@@ -125,6 +125,40 @@ public class InventoryControllerTests
         Assert.Equal(0u, containers.GetItem(1)!.ItemId); // padded empty frame
     }
 
+    [Fact]
+    public void SessionTableClearRebuildsInventoryWithoutOldObjects()
+    {
+        var (layout, grid, containers, _, _, _, _, _) = BuildLayout();
+        var objects = new ClientObjectTable();
+        SeedContained(objects, 0xAu, Player, slot: 0);
+        SeedBag(objects, 0xCu, slot: 1);
+        Bind(layout, objects);
+        Assert.Equal(0xAu, grid.GetItem(0)!.ItemId);
+        Assert.Equal(0xCu, containers.GetItem(0)!.ItemId);
+
+        objects.Clear();
+
+        Assert.Equal(0u, grid.GetItem(0)!.ItemId);
+        Assert.Equal(0u, containers.GetItem(0)!.ItemId);
+    }
+
+    [Fact]
+    public void GenerationReplacementRemovesOldOwnedProjectionAndSelection()
+    {
+        var (layout, grid, _, _, _, _, _, _) = BuildLayout();
+        var objects = new ClientObjectTable();
+        SeedContained(objects, 0xAu, Player, slot: 0);
+        var selection = new SelectionState();
+        selection.Select(0xAu, SelectionChangeSource.Inventory);
+        Bind(layout, objects, selection: selection);
+        Assert.Equal(0xAu, grid.GetItem(0)!.ItemId);
+
+        objects.ReplaceGeneration(WorldReplacement(0xAu), generation: 2);
+
+        Assert.Equal(0u, grid.GetItem(0)!.ItemId);
+        Assert.Null(selection.SelectedObjectId);
+    }
+
     [Fact]
     public void Populate_uses_manifest_container_hint_before_create_object_details()
     {
@@ -557,6 +591,30 @@ public class InventoryControllerTests
 
     private static ItemDragPayload Payload(uint obj) => new(obj, ItemDragSource.Inventory, 0, new UiItemSlot());
 
+    private static WeenieData WorldReplacement(uint guid) => new(
+        Guid: guid,
+        Name: "replacement",
+        Type: ItemType.Misc,
+        WeenieClassId: 1,
+        IconId: 0,
+        IconOverlayId: 0,
+        IconUnderlayId: 0,
+        Effects: 0,
+        Value: null,
+        StackSize: null,
+        StackSizeMax: null,
+        Burden: null,
+        ContainerId: null,
+        WielderId: null,
+        ValidLocations: null,
+        CurrentWieldedLocation: null,
+        Priority: null,
+        ItemsCapacity: null,
+        ContainersCapacity: null,
+        Structure: null,
+        MaxStructure: null,
+        Workmanship: null);
+
     [Fact]
     public void Drop_onOccupiedGridCell_insertsBefore_andMovesLocally()
     {