Add a privacy policy, document report, and serve the fonts ourselves

The new Privacy page, linked from the footer, says what reaches Federated
Computer: what our servers see when machines install, update or check
for updates, and what error reports contain, where they go and how long
they're kept. The Utilities page describes report, and the System page
lists it among the installed commands.

Inter and JetBrains Mono are now served from the site, with their
licenses, instead of from Google Fonts, so a visit contacts no third
party.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

layouts/partials/head.html

@@ -6,7 +6,6 @@
 <link rel="icon" href="{{ "favicon.ico" | relURL }}?v=2" sizes="32x32">
 <link rel="icon" href="{{ "favicon.svg" | relURL }}?v=2" type="image/svg+xml">
 <link rel="apple-touch-icon" href="{{ "apple-touch-icon.png" | relURL }}?v=2">
-<link rel="preconnect" href="https://fonts.googleapis.com">
-<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
-<link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap" rel="stylesheet">
+<link rel="preload" href="{{ "fonts/inter-latin.woff2" | relURL }}" as="font" type="font/woff2" crossorigin>
+<link rel="stylesheet" href="{{ "css/fonts.css" | relURL }}">
 <link rel="stylesheet" href="{{ "css/style.css" | relURL }}">