Testing and fixtures

Run the fixture runner over a directory:

Status: Current.

kalcite test tests/klc

It recursively discovers .klc files. A normal fixture must compile. Put // kalcite: expect-error on the first non-empty line when a fixture must fail. Text after the directive must occur in the emitted diagnostic.

// kalcite: expect-error expected `}`
public class Broken extend Game {

Organize fixtures by visible behaviour: language/, scenes/, ui/, diagnostics/, and codegen/. Keep one compiler contract per fixture. Use Rust unit tests for individual implementation details and project-check for a complete manifest/scene/asset contract.