chore: ignore local build artifacts

.gitignore

@@ -70,3 +70,12 @@ doc/plan/S0/
 
 # C# Dev Kit language service cache
 *.csproj.lscache
+
+# Local build check outputs
+/server/_buildcheck*/
+
+# Generated .NET artifacts
+Admin.NET.Application.dll
+Admin.NET.Core.pdb
+Admin.NET.Plugin.*.deps.json
+Admin.NET.*.xml