Emit self-hosted fonts by importing from JS, not CSS @import

Firefox's console was spammed with "downloadable font: download failed
status=2147746065" for every @fontsource family — Inter, Alfa Slab One,
JetBrains Mono. Root cause: the built CSS referenced
./files/inter-latin-400-normal.woff2 but no font files were ever emitted
to build/client/_app/immutable/assets/.

Vite's CSS `@import` inlines the imported file's *text* but doesn't
crawl the resulting url() references to emit their assets. Since
tokens.css was doing `@import '@fontsource/inter/400.css'` and being
pulled into +layout.svelte via a Svelte <style> @import, the fonts
lived entirely in CSS space where Vite's asset emission never saw them.

Moved the @fontsource imports into src/lib/ui/styles/fonts.ts and
side-effect-import that module from +layout.svelte's <script>. JS
imports go through the module graph, so Vite walks the CSS, sees the
url() references, and emits the woff/woff2 binaries.

Verified: build now emits 80 font files (14 subsets × 5-6 weights)
into build/client/_app/immutable/assets/ and the CSS url()s resolve
to the correct hashed filenames in the same directory.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/lib/ui/styles/fonts.ts

@@ -0,0 +1,16 @@
+// Font imports for the Electric Cherry design system.
+//
+// These live in a JS module (not a CSS `@import` chain) because Vite's
+// CSS processor inlines @import'd CSS as text but doesn't crawl its
+// url() references to emit the referenced woff/woff2 files as build
+// assets. Importing the CSS from JS puts it on the module graph, which
+// Vite *does* walk, so the font binaries end up in
+// build/client/_app/immutable/assets/files/.
+
+import '@fontsource/alfa-slab-one/400.css';
+import '@fontsource/inter/400.css';
+import '@fontsource/inter/500.css';
+import '@fontsource/inter/600.css';
+import '@fontsource/inter/700.css';
+import '@fontsource/jetbrains-mono/400.css';
+import '@fontsource/jetbrains-mono/500.css';

src/lib/ui/styles/tokens.css

@@ -1,14 +1,11 @@
 /* Electric Cherry — design tokens.
    Named after the perk-a-cola from Mob of the Dead (CoD Zombies):
-   deep cherry-red art-deco label + electric cyan discharge. */
+   deep cherry-red art-deco label + electric cyan discharge.
 
-@import '@fontsource/alfa-slab-one/400.css';
+   Font @import chains live in src/lib/ui/styles/fonts.ts and are pulled
-@import '@fontsource/inter/400.css';
+   in by +layout.svelte via JS import — Vite's CSS `@import` inlines the
-@import '@fontsource/inter/500.css';
+   text but doesn't emit the url()-referenced woff files as assets, so
-@import '@fontsource/inter/600.css';
+   we need the JS module graph to see them. */
-@import '@fontsource/inter/700.css';
-@import '@fontsource/jetbrains-mono/400.css';
-@import '@fontsource/jetbrains-mono/500.css';
 
 :root {
     /* Cherry — surfaces + primary */

src/routes/+layout.svelte

@@ -4,6 +4,9 @@
     import { startServerStream } from '$ui/stores/servers.js';
     import { page } from '$app/stores';
     import BrandMark from '$ui/components/BrandMark.svelte';
+    // Side-effect import — puts @fontsource CSS on Vite's module graph so
+    // the referenced woff/woff2 files get emitted into the build.
+    import '$ui/styles/fonts.js';
 
     interface Props { children: import('svelte').Snippet }
     let { children }: Props = $props();