The pwa-manifest e2e now asserts the shipped 32x32 PNG is a valid non-empty
PNG of the declared dimensions, that the PNG link precedes the SVG link in
the built index.html (the spec selects the last equally appropriate icon),
and that the light fill lives inside the dark-scheme media query while the
light-mode default stays black.
favicon.svg embeds @media (prefers-color-scheme: dark) so the DeepSeek
mark turns white under a dark browser scheme; index.html and the install
manifest gain a 32x32 PNG fallback (brand blue) for Safari, which cannot
render SVG favicons. pwa-manifest.e2e.ts pins the PNG link, both manifest
icons, and the dark media query.
