Deletion choices

Run dotnet run --project examples/Deletion -c Release with .NET 8.

The program checks caller-managed deletion, per-call checks, the pair-based helper, outer throw/ignore decorators, incoming-usage rejection, cascading and snapshot bulk deletion. It runs each recipe for both united and split heap-backed stores, creates at most five links per scenario, and fails if results differ from the documented contract. See the C# guide and shared design guidelines.