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/Theriapolis.Tests.csproj

@@ -0,0 +1,28 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Library</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <RootNamespace>Theriapolis.Tests</RootNamespace>
+    <LangVersion>12</LangVersion>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk"       Version="17.8.0" />
+    <PackageReference Include="xunit"                        Version="2.6.2" />
+    <PackageReference Include="xunit.runner.visualstudio"    Version="2.5.4">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\Theriapolis.Core\Theriapolis.Core.csproj" />
+  </ItemGroup>
+  <!-- Copy content data files so tests can load macro_template.json and biomes.json -->
+  <ItemGroup>
+    <Content Include="..\Content\Data\**\*"
+             Link="Data\%(RecursiveDir)%(Filename)%(Extension)"
+             CopyToOutputDirectory="PreserveNewest" />
+  </ItemGroup>
+</Project>