fix: fix: bundled dust cleanup — site (#209)

- Add grid-template-columns: 1fr to .values grid (issue #168)
- Add site/README.md documenting og-image.jpg regeneration and
  branding update process (issues #162, #169)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

site/README.md

@@ -0,0 +1,40 @@
+# site/
+
+Static landing page for disinto.ai.
+
+## Files
+
+- `index.html` — landing page
+- `og-image.jpg` — Open Graph image used for social sharing previews (`og:image` / `twitter:image`)
+- `al76.jpg` / `al76.webp` — hero image (Robot AL-76)
+- `favicon.ico`, `favicon-192.png`, `apple-touch-icon.png` — favicons
+
+## Regenerating og-image.jpg
+
+`og-image.jpg` is a static binary asset committed to the repo. It is not
+generated at build time. The recommended dimensions are **1200×630 px** (the
+standard Open Graph image size).
+
+To regenerate it:
+
+1. Open a design tool (Figma, GIMP, Inkscape, etc.).
+2. Create a canvas at 1200×630 px using the site color palette:
+   - background `#0a0a0a`, foreground `#e0e0e0`, accent `#c8a46e`
+3. Include the Disinto logotype / tagline and any relevant branding.
+4. Export as JPEG (quality ≥ 85) and save to `site/og-image.jpg`.
+5. Commit the updated file.
+
+## Updating og-image.jpg when branding changes
+
+Whenever the brand identity changes (logo, color palette, tagline), update
+`og-image.jpg` following the steps above. Checklist:
+
+- [ ] New image is 1200×630 px
+- [ ] Colors match the current CSS variables in `index.html` (`:root` block)
+- [ ] Tagline / copy matches the `<title>` and `<meta name="description">` in `index.html`
+- [ ] File committed and pushed before deploying the updated `index.html`
+
+Social platforms cache og:image aggressively. After deploying, use the
+[Open Graph debugger](https://developers.facebook.com/tools/debug/) and
+[Twitter Card validator](https://cards-dev.twitter.com/validator) to
+invalidate their caches.

site/index.html

@@ -150,6 +150,7 @@
     /* Value blocks */
     .values {
       display: grid;
+      grid-template-columns: 1fr;
       gap: 1px;
       background: var(--border);
       margin-bottom: 3rem;