AGENTS.md: how to run the game without the C++ build tools

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

AGENTS.md

@@ -42,6 +42,10 @@ hook-based, so upstream can still be merged.
 - `dotnet build Vocaluxe/Vocaluxe.csproj -c DebugWin -p:Platform=x64` (the whole solution also builds the native
   `PitchTracker`, which needs Visual Studio's C++ tools).
 - `dotnet test Tests/Tests.csproj -c DebugWin -p:Platform=x64`
+- Running the game (`Output\Vocaluxe.exe`) without the C++ tools: take `libs/unmanaged/x64/PitchTracker.dll` (and the
+  `Themes/Vocaluxe 2024/*.mp4` videos) from the upstream Nightly zip
+  (github.com/Vocaluxe/Vocaluxe/releases/tag/Nightly, `Vocaluxe_Nightly_Windows_x64.zip`); the PitchTracker source is
+  unchanged in this fork. Both are gitignored. Data and `Config.xml` are in `Output` (non-installer builds).
 - Building rewrites the copyright year in `Vocaluxe/Properties/AssemblyInfo.cs`; don't commit that.
 - Don't use `dotnet sln add`: it rewrites the configuration table of `Vocaluxe.sln`. Copy the lines of `VocaluxeWeb`.
 - New `config.xml` fields must also go into `Tests/VocaluxeLib/XML/TestFiles/SConfig.xml` (round-trip test; CRLF).