Fix safe recursive traversal crashes (#54/#73)

[DamianEdwards]

Fixes #54
Fixes #73

Summary

• Treat delegates, reflection types, and known JSON/dynamic framework payload/configuration types as terminal during recursive validation.
• Skip terminal runtime values reached through polymorphic/object properties instead of swallowing arbitrary property getter exceptions.
• Add regression coverage for Func, System.Text.Json.JsonSerializerOptions, and a JToken-like throwing getter.

Testing

• dotnet restore .\MiniValidation.slnx --verbosity minimal
• dotnet build .\MiniValidation.slnx --configuration Release --no-restore --verbosity minimal
• dotnet test .\tests\MiniValidation.UnitTests\MiniValidation.UnitTests.csproj --configuration Release --no-restore --no-build --verbosity minimal