NuGet package missing build/GoudEngine.targets — 60x overhead vs local build

[aram-devdocs]

Bug

GoudEngine NuGet 0.0.841 does not include the build/GoudEngine.targets file in the package. This file is responsible for copying the native library (libgoud_engine.dylib) to the output directory root, where .NET's P/Invoke loader finds it directly.

Without this file, the native library stays buried in runtimes/osx-arm64/native/ and the .NET runtime uses a fallback resolution path.

Impact

Throne (using NuGet 0.0.841) gets 1.1 FPS with 282 entities.
Character sandbox (using local project-reference to same code) gets 57 FPS with 280 agents.

The overhead per frame is ~790ms for the NuGet path vs ~14ms for local. Sim and render times are comparable.

Reproduction

1. Reference GoudEngine 0.0.841 from NuGet in any C# project
2. Run the project and measure frame timing
3. Compare with the same project using a local ProjectReference to sdks/csharp

Expected

The NuGet package should include build/GoudEngine.targets so consuming projects get the native library copied to their output root automatically (matching the local build behavior).

Affected Versions

• 0.0.841 (confirmed)
• Likely 0.0.840 and earlier as well

Workaround

Consumers can add a manual copy target in their .csproj:

<Target Name="CopyGoudEngineNativeLib" AfterTargets="Build">
  <PropertyGroup>
    <GoudNativeLib Condition="...">$(NuGetPackageRoot)goudengine/VERSION/runtimes/osx-arm64/native/libgoud_engine.dylib</GoudNativeLib>
  </PropertyGroup>
  <Copy SourceFiles="$(GoudNativeLib)" DestinationFolder="$(OutputPath)" SkipUnchangedFiles="true" />
</Target>

[aram-devdocs]

Addressed in #705: the C# SDK csproj (and its scaffolding generator) now pack build/GoudEngine.targets into the NuGet package, so consumers get the MSBuild targets and the native library resolves via the fast path instead of the slow P/Invoke fallback. Re-verify the ~60x overhead is gone on the next published package.

[aram-devdocs]

Closing as fixed — verified against current code: sdks/csharp/GoudEngine.csproj:27 packs build/GoudEngine.targets (Pack="true" PackagePath="build/") and line 34 imports it. The targets file that copies the native lib to the consumer output is present in the package. Residual path-preference hardening is folded into ENG2-P0-12.