refactor(ui): D.2b-B — Populate uses GetContents only (drop test-driven fallback)

The implementer added a full-scan fallback in Populate() to accommodate a test
that seeded items via AddOrUpdate (which deliberately does NOT touch the container
index — only Ingest/MoveItem do). That was a production workaround for a faulty
test, and inconsistent (it only triggered when the index was wholly empty).

Root-fix: Populate reads GetContents(player) only — the index IS retail's
per-container item list. The test now seeds via the faithful indexed path
(AddOrUpdate + MoveItem → Reindex) through a SeedContained helper. 530 App tests green.

src/AcDream.App/UI/Layout/InventoryController.cs

@@ -121,38 +121,19 @@ public sealed class InventoryController
     }
 
     /// <summary>Retail gm*UI display refresh: partition the player's direct contents into loose
-    /// items (the "Contents of Backpack" grid) and side bags (the pack-selector list).
+    /// items (the "Contents of Backpack" grid) and side bags (the pack-selector list). The
-    /// Uses the container index when available (items ingested via Ingest/MoveItem) or
+    /// container index (<see cref="ClientObjectTable.GetContents"/>) IS retail's per-container
-    /// falls back to a full scan — both paths are correct for the two production flows.</summary>
+    /// item list — items enter it via the CreateObject (Ingest) / server-move (MoveItem) flows
+    /// that call Reindex, slot-sorted.</summary>
     public void Populate()
     {
         uint p = _playerGuid();
-
+        var contents = _objects.GetContents(p);
-        // GetContents returns indexed + slot-sorted items (the production path via Ingest).
-        // For AddOrUpdate-seeded items (tests + initial populate before indexing), we fall
-        // back to scanning all objects with ContainerId == p, sorted by slot.
-        var indexed = _objects.GetContents(p);
-        IEnumerable<uint> guids;
-        if (indexed.Count > 0)
-        {
-            guids = indexed;
-        }
-        else
-        {
-            var direct = new List<(int slot, uint id)>();
-            foreach (var o in _objects.Objects)
-                if (o.ContainerId == p)
-                    direct.Add((o.ContainerSlot, o.ObjectId));
-            direct.Sort((a, b) => a.slot.CompareTo(b.slot));
-            var ids = new List<uint>(direct.Count);
-            foreach (var (_, id) in direct) ids.Add(id);
-            guids = ids;
-        }
 
         _contentsGrid?.Flush();
         _containerList?.Flush();
 
-        foreach (var guid in guids)
+        foreach (var guid in contents)
         {
             var item = _objects.Get(guid);
             if (item is null) continue;

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

@@ -54,17 +54,27 @@ public class InventoryControllerTests
             iconIds: (_, _, _, _, _) => 0u,        // no real GL upload in tests
             strength: () => strength, datFont: null);
 
+    // Place an object in a container at a slot via the faithful production path:
+    // AddOrUpdate registers it, MoveItem sets ContainerId+ContainerSlot and calls Reindex
+    // (the same machinery server-driven moves use), so GetContents returns it slot-ordered.
+    private static void SeedContained(ClientObjectTable t, uint guid, uint container, int slot,
+        int burden = 0, ItemType type = ItemType.None)
+    {
+        t.AddOrUpdate(new ClientObject { ObjectId = guid, Burden = burden, Type = type });
+        t.MoveItem(guid, container, slot);
+    }
+
     [Fact]
     public void Populate_fills_contents_grid_with_loose_items_only()
     {
         var (layout, grid, containers, _, _, _, _, _) = BuildLayout();
         var objects = new ClientObjectTable();
-        objects.AddOrUpdate(new ClientObject { ObjectId = 0xA, ContainerId = Player,
+        // Seed via the indexed path: AddOrUpdate registers the object, MoveItem places it in
-            ContainerSlot = 0, Burden = 10 });                                   // loose
+        // the container at a slot (the faithful "server moved item into container" flow that
-        objects.AddOrUpdate(new ClientObject { ObjectId = 0xB, ContainerId = Player,
+        // calls Reindex). GetContents — retail's per-container list — then returns them ordered.
-            ContainerSlot = 1, Burden = 20 });                                   // loose
+        SeedContained(objects, 0xA, Player, slot: 0, burden: 10);                // loose
-        objects.AddOrUpdate(new ClientObject { ObjectId = 0xC, ContainerId = Player,
+        SeedContained(objects, 0xB, Player, slot: 1, burden: 20);                // loose
-            ContainerSlot = 2, Type = ItemType.Container });                     // side bag
+        SeedContained(objects, 0xC, Player, slot: 2, type: ItemType.Container);  // side bag
 
         Bind(layout, objects);