feat(eventbus): add platform runtimes and benchmarks

Add the Entities NativeQueue adapter, standalone .NET runtime and source generator, reproducible smoke coverage, and Unity benchmark assets for EventBus 2.0.

.gitignore

@@ -7,6 +7,9 @@
 /[Ll]ibrary/
 /[Tt]emp/
 /[Oo]bj/
+/DotNet/**/[Bb]in/
+/DotNet/**/[Oo]bj/
+/TestResults/
 /[Bb]uild/
 /[Bb]uilds/
 /[Ll]ogs/
@@ -56,6 +59,16 @@ ExportedObj/
 *.opendb
 *.VC.db
 
+# Tracked source project for rebuilding ShrinkModFramework external DLL fixtures.
+!Tools/ShrinkModFixtureBuilder/ShrinkModFixtureBuilder.csproj
+Tools/ShrinkModFixtureBuilder/bin/
+Tools/ShrinkModFixtureBuilder/obj/
+
+# Tracked standalone .NET projects for ShrinkEventBus runtime and generator validation.
+!DotNet/ShrinkEventBus.Core/ShrinkEventBus.Core.csproj
+!DotNet/ShrinkEventBus.Generator/ShrinkEventBus.Generator.csproj
+!DotNet/ShrinkEventBus.Smoke/ShrinkEventBus.Smoke.csproj
+
 # Unity3D generated meta files
 *.pidb.meta
 *.pdb.meta