feat(ui): D.2b inventory finish — contents grid shows full main-pack capacity

The contents grid now pads empty slot frames up to the main-pack capacity
(player ItemsCapacity, default 102 per retail "up to 102 items"), so the pack
reads like retail's fixed 102-slot grid you scroll through — not just the loose
items. Mirrors the side-bag column padding. Three existing grid tests updated
for the now-padded count; new test covers the 102-pad.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

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

@@ -36,6 +36,7 @@ public sealed class InventoryController
     private const float ContentsCellPx = 32f;   // gm3DItemsUI grid (192x96 = 6x3 of 32px)
     private const float BackpackCellPx = 36f;   // gmBackpackUI column cells (0x100001C9/CA = 36px)
     private const int   SideBagSlots   = 7;     // 0x100001CA is 36x252 = 7 slots
+    private const int   MainPackSlots  = 102;   // retail main-pack capacity (Wiki: "up to 102 items")
 
     private readonly ClientObjectTable _objects;
     private readonly Func<uint> _playerGuid;
@@ -179,6 +180,18 @@ public sealed class InventoryController
             list.AddItem(cell);
         }
 
+        // Contents grid: show the FULL main-pack capacity (default 102) — occupied slots + empty
+        // frames — so the pack reads like retail (a fixed 102-slot grid you scroll), not just the
+        // loose items. The grid shows the SELECTED pack (default = the main pack / player); side-pack
+        // contents are a container-switch (later). Capacity = the player's ItemsCapacity, else 102.
+        if (_contentsGrid is not null)
+        {
+            int cap = _objects.Get(p)?.ItemsCapacity ?? 0;
+            int slots = cap > 0 ? cap : MainPackSlots;
+            while (_contentsGrid.GetNumUIItems() < slots)
+                _contentsGrid.AddItem(new UiItemSlot { SpriteResolve = _contentsGrid.SpriteResolve });
+        }
+
         // Side-bag column: pad with empty slot frames up to the player's container capacity
         // (clamped to the 7-slot column) so it reads like retail (bags on top, empty frames
         // below) rather than one lone cell. Falls back to the full 7 slots when capacity is

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

@@ -80,9 +80,10 @@ public class InventoryControllerTests
 
         Bind(layout, objects);
 
-        Assert.Equal(2, grid.GetNumUIItems());          // 2 loose
+        Assert.Equal(102, grid.GetNumUIItems());        // 2 loose + 100 empty (main-pack capacity)
         Assert.Equal(0xAu, grid.GetItem(0)!.ItemId);
         Assert.Equal(0xBu, grid.GetItem(1)!.ItemId);
+        Assert.Equal(0u, grid.GetItem(2)!.ItemId);      // padded empty
         Assert.Equal(7, containers.GetNumUIItems());     // 1 side bag + 6 empty (no capacity → 7-slot column)
         Assert.Equal(0xCu, containers.GetItem(0)!.ItemId);
         Assert.Equal(0u, containers.GetItem(1)!.ItemId); // padded empty frame
@@ -101,7 +102,7 @@ public class InventoryControllerTests
 
         Bind(layout, objects);
 
-        Assert.Equal(1, grid.GetNumUIItems());          // only the loose item
+        Assert.Equal(102, grid.GetNumUIItems());        // 1 loose + 101 empty (main-pack capacity)
         Assert.Equal(0xAu, grid.GetItem(0)!.ItemId);
         Assert.Equal(7, containers.GetNumUIItems());    // 7 empty slots (no bags; the equipped item isn't here)
         Assert.Equal(0u, containers.GetItem(0)!.ItemId);
@@ -123,12 +124,13 @@ public class InventoryControllerTests
         var (layout, grid, _, _, _, _, _, _) = BuildLayout();
         var objects = new ClientObjectTable();
         Bind(layout, objects);
-        Assert.Equal(0, grid.GetNumUIItems());
+        Assert.Equal(102, grid.GetNumUIItems());        // empty grid still shows the full 102-slot pack
+        Assert.Equal(0u, grid.GetItem(0)!.ItemId);      // slot 0 empty before the add
 
         objects.Ingest(new WeenieData(0xA, "Sword", ItemType.MeleeWeapon, 1, 0, 0, 0, 0,
             null, null, null, 5, Player, null, null, null, null, null, null, null, null, null));
 
-        Assert.Equal(1, grid.GetNumUIItems());
+        Assert.Equal(102, grid.GetNumUIItems());        // still 102; the item fills slot 0
         Assert.Equal(0xAu, grid.GetItem(0)!.ItemId);
     }
 
@@ -205,6 +207,23 @@ public class InventoryControllerTests
         Assert.Same(grid.Scroll, bar.Model);            // the bar drives the grid's scroll
     }
 
+    [Fact]
+    public void Contents_grid_pads_empty_slots_to_main_pack_capacity()
+    {
+        // The grid shows the full main-pack capacity (default 102) — occupied + empty — so the
+        // pack reads like retail's fixed 102-slot grid you scroll, not just the loose items.
+        var (layout, grid, _, _, _, _, _, _) = BuildLayout();
+        var objects = new ClientObjectTable();
+        objects.AddOrUpdate(new ClientObject { ObjectId = Player, ItemsCapacity = 102 });
+        SeedContained(objects, 0xA, Player, slot: 0, burden: 5);    // one loose item
+
+        Bind(layout, objects);
+
+        Assert.Equal(102, grid.GetNumUIItems());        // 1 item + 101 empty frames = 102
+        Assert.Equal(0xAu, grid.GetItem(0)!.ItemId);
+        Assert.Equal(0u, grid.GetItem(50)!.ItemId);     // a padded empty slot
+    }
+
     [Fact]
     public void Side_bag_column_pads_empty_slots_up_to_capacity()
     {