Add ScriptSandboxTests cases for all forbidden-namespace deny-list
vectors that lacked test coverage: System.Threading.Thread,
System.Threading.Tasks.Task.Run (newly denied per Core.Scripting-003),
System.Runtime.InteropServices.Marshal, and Microsoft.Win32.Registry.
The 001/002 type-granular and node-form vectors were already covered by
the -001/-002 resolution commits. All 79 tests pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
a17de80cdb