Write, fix, or review the browser journeys in tests/stand/ui/ — Playwright (Python, sync API) against a deployed Insight stand with a real Keycloak sign-in. Covers the governing UI-vs-API rule and how to justify a browser test in writing, accessibility-first locators, the page-object/flows split, manifest-derived expectations, URL/deep-link validation, and real browser downloads. Use for any request to write, add, fix or review a committed browser test in this repository — 'add a Playwright test for X', 'the UI test is failing', 'turn this scenario into a browser journey', 'add a deep-link or download regression' — and for anything under tests/stand/ui/. For HTTP contract tests use stand-api-test; playwright-cli is for driving a browser interactively at a prompt and for Playwright's own CLI — reach for it only when nothing will be committed under tests/stand/ui/; drive-ui is for looking at a stand by hand.