How to run and verify the `*_demo.html` files scattered across packages (e.g. packages/frontend/navi/src/control/demos/). Use when the user explicitly asks to load a demo in a browser / Playwright to check it works — not proactively (see .agents/instructions.md's "never verify on your own initiative" constraint).
Workflow for creating a new UI component in @jsenv/navi. Use when implementing a new frontend component from scratch.
How to write and run tests in @jsenv/core. Use when adding, running, or understanding tests in any package of this monorepo.