Make command scenarios discover validators

[woksin]

Summary

Command scenarios now exercise command validators discovered by Arc, including validators with scenario-provided dependencies and manual overrides.

Added

• Specs covering automatic dependency-backed command validator execution in CommandScenario<TCommand>.
• Specs covering missing validator dependencies and manual concrete validator overrides.
• A spec proving validators can receive interface-backed scoped dependencies from scenario.Services without manually registering the validator.
• JavaScript command result specs covering primitive command responses.

Changed

• CommandScenario<TCommand> registers discovered validators in its isolated service provider so scenario validation matches runtime command execution without leaking validators or dependencies across scenarios.
• Existing concrete validator registrations are preserved; scenarios only add missing validator registrations, so custom factories/lifetimes and manual overrides still win.
• JavaScript CommandResult now preserves primitive command responses directly instead of passing strings, numbers, and booleans through object deserialization.
• Added a narrow CA2000 ownership suppression for the query-health observable wrapper so Release builds recognize the existing disposal ownership pattern.

[github-actions]

NuGet packages for this PR, e.g. Cratis.Arc:
https://github.com/cratis/arc/packages/1655206?version=20.40.3