feat(02-01): install Montserrat + PT Serif, wire font imports, pin dark variant

- Add @fontsource/montserrat@^5.2.8 and @fontsource/pt-serif@^5.2.8 to dependencies
- Prepend six @fontsource @import lines to tailwind.css before @import tailwindcss
- Add LOAD-BEARING comment block around @custom-variant dark (PR arthelokyo#646 flicker fix)
- pnpm build exits 0, no googleapis.com in dist

Author: chaarirami

package.json

@@ -25,6 +25,8 @@
     "@astrojs/rss": "^4.0.18",
     "@astrojs/sitemap": "^3.7.2",
     "@astrolib/seo": "^1.0.0-beta.8",
+    "@fontsource/montserrat": "^5.2.8",
+    "@fontsource/pt-serif": "^5.2.8",
     "astro": "^6.1.8",
     "astro-embed": "^0.13.0",
     "astro-icon": "^1.1.5",

pnpm-lock.yaml

@@ -1,8 +1,18 @@
+@import '@fontsource/montserrat/400.css';
+@import '@fontsource/montserrat/500.css';
+@import '@fontsource/montserrat/600.css';
+@import '@fontsource/montserrat/700.css';
+
+@import '@fontsource/pt-serif/400.css';
+@import '@fontsource/pt-serif/700.css';
+
 @import 'tailwindcss';
 
 @plugin '@tailwindcss/typography';
 
+/* LOAD-BEARING: dark mode variant — do NOT remove or modify (PR #646 flicker fix) */
 @custom-variant dark (&:where(.dark, .dark *));
+/* end dark mode variant */
 @custom-variant intersect (&:not([no-intersect]));
 
 @theme {