Koru Adds Experimental .NET Backend

Koru’s third backend is more than a port: it validates whether the language’s continuation model survives outside Zig while exposing bugs that a single-target compiler could hide.

• –Static generic handlers let emitted C# approach direct-call performance without delegate allocation or virtual dispatch.
• –The backend surfaced real cross-target issues, including saturating subtraction, reserved-name collisions, and untested tree paths.
• –Record payloads now use named tuples, reducing dynamic dispatch and boxing in common effect paths.
• –Coverage is still partial: pumps, slices, pointer types, qualified protos, and several standard-library facets remain unsupported.