Add product website (deploy target: noo.ayushya.dev)

A single-page, static site under website/ - no build step, no
framework, just HTML/CSS/vanilla JS plus the two Google Fonts the app
already uses. Colors, radii, type scale and motion timing are copied
from lib/theme/design_tokens.dart so it reads as the same product as
the app, not a separate marketing skin.

Sections: hero with an exploded, parallaxing stack of the app's own UI
pieces (file row, photo grid, accent swatches, a toggle, the floating
bar) that drift apart on scroll and tilt toward the pointer; feature
highlights; a Customize section with two live interactive demos
(accent color, floating vs attached bottom bar); a privacy section
covering Login Flow v2; and a closing CTA.

GitHub/download links are placeholders (documented in website/README.md)
until real release URLs exist.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

website/README.md

@@ -0,0 +1,38 @@
+# Noo website
+
+The product site for Noo, meant to be deployed at `noo.ayushya.dev`.
+
+Static HTML/CSS/vanilla JS, no build step and no dependencies beyond the
+two Google Fonts already used by the app (Schibsted Grotesk, Instrument
+Sans). Colors, radii, type scale and motion timing are copied from
+`lib/theme/design_tokens.dart` so the site and the app read as the same
+product.
+
+## Files
+
+- `index.html` — the whole page (hero, features, customize, privacy, CTA).
+- `styles.css` — all styling, incl. the design tokens as CSS custom
+  properties and a dark-mode variant (`prefers-color-scheme` and an
+  explicit `data-theme` override for a future toggle).
+- `script.js` — mobile nav, the hero's exploded-layer parallax
+  (scroll + pointer), the two interactive Customize demos (accent color,
+  bottom bar style), and scroll-reveal.
+- `favicon.svg`.
+
+## Local preview
+
+Any static file server works, e.g.:
+
+```bash
+cd website
+python3 -m http.server 8000
+```
+
+Then open `http://localhost:8000`.
+
+## Deploying
+
+Point any static host (Cloudflare Pages, Netlify, GitHub Pages, or a
+plain nginx `root`) at this folder - there's nothing to build. Update the
+`https://github.com` placeholder links and the two "Download for..."
+buttons in `index.html` once real release links exist.