Encore Testing

Sets up Vitest testing for Encore.ts applications with the basic configuration you need to start writing tests. If you're building backend services with Encore's TypeScript framework, this gives you the standard testing scaffolding rather than hunting through docs. It's a minimal setup skill, really just the Vitest dependency and package.json scripts, so you'll still need to write your actual test files. Nothing fancy here, but it handles the boring part of getting a test runner in place so you can focus on testing your API endpoints and service logic.