feat(studio): FixtureProvider — sample data populates the 2-D panels

Task 4 of the UI Studio plan: adds SampleData (static ClientObjectTable
builder with a synthetic player, 6 loose items, 2 side bags, and 3 equipped
pieces) and FixtureProvider (switches on layoutId and calls the production
controller Bind methods — VitalsController, ToolbarController,
InventoryController — so the studio previews panels with plausible data
instead of empty widgets).

Icon ids approach: raw-resolve stub — resolves the base iconId via
RenderStack.ResolveChrome and returns the GL handle directly. This is v1
(single-layer icon); the full 5-layer IconComposer composite is a live-game
concern, not a layout-preview concern.

StudioWindow wires FixtureProvider.Populate after _source.Load; the
ClientObjectTable is stored on _objects so controller event subscriptions
(ObjectAdded/ObjectMoved) remain live for the window's lifetime.

4 new FixtureProviderTests (SampleTable_hasPackContents,
SampleTable_hasWeaponAndArmor, SampleTable_hasEquippedItems,
SampleTable_hasSideBags) — all pass. Full App suite: 602 passed / 2
skipped (pre-existing) / 0 failed. Build green.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/AcDream.App.Tests/Studio/FixtureProviderTests.cs

@@ -0,0 +1,105 @@
+using AcDream.App.Studio;
+using AcDream.Core.Items;
+
+namespace AcDream.App.Tests.Studio;
+
+/// <summary>
+/// Unit tests for <see cref="FixtureProvider"/> and <see cref="SampleData"/>.
+/// These tests have NO GL/dat dependency — they only exercise the in-memory
+/// ClientObjectTable population that FixtureProvider uses.
+/// </summary>
+public class FixtureProviderTests
+{
+    /// <summary>
+    /// SampleData.BuildObjectTable() must place at least 6 items in the
+    /// player's main pack (ContainerId == PlayerGuid) and the player object
+    /// itself must exist with the right capacities.
+    /// </summary>
+    [Fact]
+    public void SampleTable_hasPackContents()
+    {
+        var t = SampleData.BuildObjectTable();
+
+        // Player object must exist.
+        var player = t.Get(SampleData.PlayerGuid);
+        Assert.NotNull(player);
+        Assert.Equal(102, player!.ItemsCapacity);
+        Assert.Equal(7,   player.ContainersCapacity);
+
+        // At least 6 loose items must be in the main pack.
+        var contents = t.GetContents(SampleData.PlayerGuid);
+        Assert.True(contents.Count >= 6,
+            $"Expected >= 6 items in player pack; got {contents.Count}");
+
+        // Verify the first item has a non-zero IconId and a recognised Type.
+        var firstId = contents[0];
+        var first = t.Get(firstId);
+        Assert.NotNull(first);
+        Assert.NotEqual(0u, first!.IconId);
+        Assert.NotEqual(ItemType.None, first.Type);
+    }
+
+    /// <summary>
+    /// Spot-check that the sample table also seeds a sword-like item
+    /// (MeleeWeapon) and a piece of armor so icon resolution has
+    /// recognisable item types to work with.
+    /// </summary>
+    [Fact]
+    public void SampleTable_hasWeaponAndArmor()
+    {
+        var t = SampleData.BuildObjectTable();
+        var contents = t.GetContents(SampleData.PlayerGuid);
+
+        bool hasMelee = false, hasArmor = false;
+        foreach (var guid in contents)
+        {
+            var obj = t.Get(guid);
+            if (obj is null) continue;
+            if ((obj.Type & ItemType.MeleeWeapon) != 0) hasMelee = true;
+            if ((obj.Type & ItemType.Armor)        != 0) hasArmor = true;
+        }
+
+        Assert.True(hasMelee, "Expected at least one MeleeWeapon in sample pack");
+        Assert.True(hasArmor,  "Expected at least one Armor item in sample pack");
+    }
+
+    /// <summary>
+    /// Sample table must include at least 1 equipped item whose
+    /// CurrentlyEquippedLocation is non-None.
+    /// </summary>
+    [Fact]
+    public void SampleTable_hasEquippedItems()
+    {
+        var t = SampleData.BuildObjectTable();
+
+        bool anyEquipped = false;
+        foreach (var obj in t.Objects)
+        {
+            if (obj.CurrentlyEquippedLocation != EquipMask.None)
+            { anyEquipped = true; break; }
+        }
+
+        Assert.True(anyEquipped, "Expected at least one equipped item in sample table");
+    }
+
+    /// <summary>
+    /// Sample table must include at least 2 side-bag containers in the
+    /// player's pack (ContainerId == PlayerGuid, Type has Container bit).
+    /// </summary>
+    [Fact]
+    public void SampleTable_hasSideBags()
+    {
+        var t = SampleData.BuildObjectTable();
+
+        int bagCount = 0;
+        foreach (var guid in t.GetContents(SampleData.PlayerGuid))
+        {
+            var obj = t.Get(guid);
+            if (obj is not null && (obj.Type & ItemType.Container) != 0)
+                bagCount++;
+        }
+
+        Assert.True(bagCount >= 2,
+            $"Expected >= 2 side-bag containers in player pack; got {bagCount}");
+    }
+}