tools/render_check.py drives the real UI in Playwright's Chromium and asserts
what a person actually sees: the login gate, live search narrowing on a spec
value, the quick-adjust buttons, the category spec template pre-filling and
switching the unit to grams, the settings and password panels, and the phone
layout at a true 390px viewport.
Playwright's own Chromium rather than the installed Chrome: headless Chrome
returns nothing while a desktop Chrome is open, silently enough that it reads
as the app being broken.
It found a real bug on its first run. The fetch helper treated any 401 as a
lapsed session, so a wrong password bounced to "Not authenticated" instead of
saying the password was wrong. 401s from the login call itself are now left to
report their own reason.
It also confirmed the CSP is doing its job from the other direction:
Playwright's wait_for_function compiles predicates with eval() and is refused,
so the check polls from Python rather than the app loosening script-src.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
