Rebuild the web landing page to the blueprint spec

Ten dark cinematic sections: fixed glass nav with a hamburger sheet, hero
with the badge/dual CTA/stats bar, a pausable 35mm film-strip marquee, the
live preset tester (5 stocks, HUD, spec bars), the three-knob custom recipe
simulator, the 6-card feature grid, the QR sharing showcase, free-vs-Pro
pricing, reviews + FAQ accordion and the final CTA/footer.

The page owns its palette and its .lp-* styles, so it renders the same in
either workspace theme, and it pulls no CDN: Syne is bundled and the six
sample negatives are vendored (see docker/README.md). Store buttons raise a
toast instead of the old alert(). The now-dead landing CSS and the unused
land.* dictionary keys are gone.

docker/README.md

@@ -47,6 +47,12 @@ project (`@shopify/react-native-skia` is aliased to `src/engine/skiaShim.ts` in
 `cinemaShader` `colorUtils` `defaultRecipes` `exifWrite` `frameUtils` `jpegDpi`
 `paramDefs` `skiaImage` `toneShader`.
 
+The landing page needs no CDN: `frontend/public/assets/Syne.woff2` is the
+bundled display face and `frontend/public/assets/samples/s*.jpg` are the six
+placeholder negatives the film strip, preset tester and QR card show (swap them
+for real graded stills whenever we have them). Its one foreign request is the
+QR image from `api.qrserver.com`, which degrades to an empty slot offline.
+
 When the app changes one of them, copy it back in — the renderer is only
 "parity" for as long as these stay in sync: