`make frontend-viewport-test` builds `dist/`, serves it from the same
digest-pinned nginx image and nginx.conf the shipping container uses, and
drives a digest-pinned headless Chrome over CDP. Viewport widths are derived
from the app's own @media breakpoints rather than a list of phone models: each
breakpoint is tested one pixel below, on, and above, plus four anchor
viewports. Assertions are on computed layout — horizontal overflow, off-screen
elements, clipped text, 44x44 tap targets, host-row reflow — not screenshots,
and each check declares the minimum elements it must find so a stale selector
fails instead of passing blind against a page it is not measuring. Kept out of
`make check`: it needs Docker and takes minutes. Proven able to fail before
being trusted.
Model: opus-4-8
SPA for real-time latency monitoring to 10 internet hosts:
- 250ms update interval with 300s history sparkline graphs
- Color-coded latency display (green <50ms to red >500ms)
- HEAD request timing with no-cors mode for cross-origin support
- Built with Vite + Tailwind CSS v4, all dependencies bundled
- Designed for static bucket deployment