Initial commit: Theriapolis baseline at port/godot branch point

Captures the pre-Godot-port state of the codebase. This is the rollback
anchor for the Godot port (M0 of theriapolis-rpg-implementation-plan-godot-port.md).
All Phase 0 through Phase 6.5 work is included; Phase 7 is in flight.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Theriapolis.Tests/Rules/SubclassResolverTests.cs

@@ -0,0 +1,116 @@
+using Theriapolis.Core.Data;
+using Theriapolis.Core.Rules.Character;
+using Xunit;
+
+namespace Theriapolis.Tests.Rules;
+
+/// <summary>
+/// Phase 6.5 M2 — SubclassResolver covers the pure look-up surface
+/// (subclass id → unlocked feature ids per level, feature def lookup).
+/// All subclass mechanics are JSON-driven; tests run against the live
+/// content set so authoring drift is caught here.
+/// </summary>
+public sealed class SubclassResolverTests
+{
+    private readonly ContentResolver _content = new(new ContentLoader(TestHelpers.DataDirectory));
+
+    [Fact]
+    public void TryFindSubclass_ReturnsDefForKnownId()
+    {
+        var def = SubclassResolver.TryFindSubclass(_content.Subclasses, "pack_forged");
+        Assert.NotNull(def);
+        Assert.Equal("fangsworn", def!.ClassId);
+    }
+
+    [Fact]
+    public void TryFindSubclass_NullForEmptyId()
+    {
+        Assert.Null(SubclassResolver.TryFindSubclass(_content.Subclasses, ""));
+        Assert.Null(SubclassResolver.TryFindSubclass(_content.Subclasses, null));
+    }
+
+    [Fact]
+    public void TryFindSubclass_NullForUnknownId()
+    {
+        Assert.Null(SubclassResolver.TryFindSubclass(_content.Subclasses, "definitely_not_a_subclass"));
+    }
+
+    [Fact]
+    public void UnlockedFeaturesAt_Level3_ReturnsFirstFeature()
+    {
+        var features = SubclassResolver.UnlockedFeaturesAt(_content.Subclasses, "pack_forged", 3);
+        Assert.NotEmpty(features);
+        Assert.Contains("packmates_howl", features);
+    }
+
+    [Fact]
+    public void UnlockedFeaturesAt_LevelWithoutEntry_ReturnsEmpty()
+    {
+        // Pack-Forged has entries at L3, L7, L10, L15, L18 — L4 is empty.
+        var features = SubclassResolver.UnlockedFeaturesAt(_content.Subclasses, "pack_forged", 4);
+        Assert.Empty(features);
+    }
+
+    [Fact]
+    public void UnlockedFeaturesAt_NullSubclassId_ReturnsEmpty()
+    {
+        Assert.Empty(SubclassResolver.UnlockedFeaturesAt(_content.Subclasses, null, 3));
+        Assert.Empty(SubclassResolver.UnlockedFeaturesAt(_content.Subclasses, "", 3));
+    }
+
+    [Fact]
+    public void ResolveFeatureDef_FindsSubclassFeature()
+    {
+        var subclass = _content.Subclasses["pack_forged"];
+        var classDef = _content.Classes["fangsworn"];
+        var fdef = SubclassResolver.ResolveFeatureDef(classDef, subclass, "packmates_howl");
+        Assert.NotNull(fdef);
+        Assert.Equal("Packmate's Howl", fdef!.Name);
+    }
+
+    [Fact]
+    public void ResolveFeatureDef_FallsThroughToClassDefForSharedIds()
+    {
+        var subclass = _content.Subclasses["pack_forged"];
+        var classDef = _content.Classes["fangsworn"];
+        // 'asi' is in the class feature_definitions (shared across subclasses).
+        var fdef = SubclassResolver.ResolveFeatureDef(classDef, subclass, "asi");
+        Assert.NotNull(fdef);
+    }
+
+    [Fact]
+    public void ResolveFeatureDef_NullForUnknownId()
+    {
+        var subclass = _content.Subclasses["pack_forged"];
+        var classDef = _content.Classes["fangsworn"];
+        Assert.Null(SubclassResolver.ResolveFeatureDef(classDef, subclass, "completely_made_up_feature"));
+    }
+
+    [Fact]
+    public void EveryClass_HasAtLeastOneSubclass()
+    {
+        // Smoke: every class declared in classes.json should resolve to at
+        // least one entry in subclasses.json.
+        foreach (var cls in _content.Classes.Values)
+        {
+            Assert.NotEmpty(cls.SubclassIds);
+            foreach (var sid in cls.SubclassIds)
+            {
+                Assert.True(_content.Subclasses.ContainsKey(sid),
+                    $"class '{cls.Id}' references unknown subclass '{sid}'");
+            }
+        }
+    }
+
+    [Fact]
+    public void EverySubclass_HasLevel3Features()
+    {
+        // M2 ship-point: every authored subclass should have at least one
+        // level-3 feature so the L3 unlock fires meaningfully.
+        foreach (var sub in _content.Subclasses.Values)
+        {
+            var l3 = SubclassResolver.UnlockedFeaturesAt(_content.Subclasses, sub.Id, 3);
+            Assert.NotEmpty(l3);
+        }
+    }
+}