Website: fix visual bugs found in a page-by-page review

- Gradient buttons showed a dark sliver on the right: the background shorthand reset
  background-origin, so the gradient repeated under the transparent border.
- Phone header: keep the brand on one line and drop the GitHub button under 480px.
- Hero pill: put the platform list on its own line on phones instead of orphaning one item.
- Privacy page: plain sections instead of open accordions whose x looked like a close button.
- Same header (GitHub button) and footer links on every page; legend spacing on the form.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

site/public/index.html

@@ -41,7 +41,7 @@
 <main>
 <section class="hero">
   <div class="wrap">
-    <span class="eyebrow"><b>Free and open source</b> · macOS · Windows · Linux · iPhone</span>
+    <span class="eyebrow"><b>Free and open source</b><span class="sep"> · </span><span class="plats">macOS · Windows · Linux · iPhone</span></span>
     <h1>Your Steam Frame, <span>managed from your desk.</span></h1>
     <p class="lede">See what the headset sees, install games and Android apps, move files and text across, and keep an eye on battery and status. All over SSH, with nothing to install on the Frame.</p>
     <div class="cta">