style(board): landscape sheets, larger sizing, and web fonts

Render A-series sheets in landscape (√2:1), size them off a single
--sheet-base variable so A2/A3/A4 keep exact ISO ratios while leaving room
for labels (which now wrap). Load Playfair Display + Cutive Mono via the
coollabs fonts API: Playfair Display for headings, Cutive Mono for the board.

nuxt.config.ts

@@ -3,4 +3,16 @@ export default defineNuxtConfig({
   compatibilityDate: '2025-07-15',
   devtools: { enabled: true },
   modules: ['@nuxt/eslint', '@nuxt/test-utils/module'],
+  css: ['~/assets/css/main.css'],
+  app: {
+    head: {
+      link: [
+        { rel: 'preconnect', href: 'https://api.fonts.coollabs.io' },
+        {
+          rel: 'stylesheet',
+          href: 'https://api.fonts.coollabs.io/css2?family=Cutive+Mono&family=Playfair+Display:wght@400;700;800&display=swap',
+        },
+      ],
+    },
+  },
 })