refactor(fonts): drop Google Fonts CDN links, preload self-hosted faces

Remove the googleapis stylesheet, both google preconnects, and the two
dead fontshare preconnects from the document head. Preload the two
render-critical faces (Inter, Space Grotesk) via Vite ?url imports.
Eliminates two third-party origins and the IP leak to Google.

src/app/ui/Layout.svelte

@@ -9,6 +9,14 @@ import { ResponsiveProvider } from '$shared/lib';
 import { cn } from '$shared/lib';
 import { Footer } from '$widgets/Footer';
 
+/*
+    Preload the two render-critical interface faces (primary + secondary).
+    `?url` resolves to the content-hashed path Vite emits, so the binary is
+    fetched immediately rather than waiting for CSS @font-face discovery.
+*/
+import interWoff2 from '../assets/fonts/inter-latin-opsz-normal.woff2?url';
+import spaceGroteskWoff2 from '../assets/fonts/space-grotesk-latin-wght-normal.woff2?url';
+
 import {
     type Snippet,
     onDestroy,
@@ -33,36 +41,21 @@ onDestroy(() => themeManager.destroy());
 <svelte:head>
     <link rel="icon" href={G} type="image/svg+xml" />
 
-    <link rel="preconnect" href="https://api.fontshare.com" />
+    <!-- Self-hosted interface fonts (see src/app/styles/fonts/fonts.css). Preload the two critical faces. -->
     <link
-        rel="preconnect"
+        rel="preload"
-        href="https://cdn.fontshare.com"
+        as="font"
-        crossorigin="anonymous"
+        type="font/woff2"
-    />
+        href={interWoff2}
-
-    <link rel="preconnect" href="https://fonts.googleapis.com" />
-    <link
-        rel="preconnect"
-        href="https://fonts.gstatic.com"
         crossorigin="anonymous"
     />
     <link
         rel="preload"
-        as="style"
+        as="font"
-        href="https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&family=Space+Grotesk:wght@300..700&family=Space+Mono:ital,wght@0,400;0,700;1,400;1,700&family=Syne:wght@800&display=swap"
+        type="font/woff2"
+        href={spaceGroteskWoff2}
+        crossorigin="anonymous"
     />
-    <link
-        rel="stylesheet"
-        href="https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&family=Space+Grotesk:wght@300..700&family=Space+Mono:ital,wght@0,400;0,700;1,400;1,700&family=Syne:wght@800&display=swap"
-        media="print"
-        onload={(e => ((e.currentTarget as HTMLLinkElement).media = 'all'))}
-    />
-    <noscript>
-        <link
-            rel="stylesheet"
-            href="https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&family=Space+Grotesk:wght@300..700&family=Space+Mono:ital,wght@0,400;0,700;1,400;1,700&family=Syne:wght@800&display=swap"
-        />
-    </noscript>
     <title>GlyphDiff | Typography & Typefaces</title>
     <meta
         name="description"