[kaiserls]

Summary

• add a no-output TypeScript type-check command
• add a Node.js unit-test layer for pure Pixi command logic
• add a VS Code extension-host smoke-test layer
• gate pre-release publishing on the full test suite
• document local testing commands and test-layer responsibilities

The unit test covers canonical Pixi environment names so display labels such as project:dev (3.12.0) are not passed to the Pixi CLI.

Validation

• tsc -p . --noEmit
• tsc -p . --outDir out
• node --test out/test/**/*.unit.test.js
• VS Code extension-host smoke test via @vscode/test-cli
• ESLint and Prettier checks