Add complete Open Graph metadata layer across all 20 pages

- Add og:title, og:description, og:image, og:url, og:type, og:site_name to BaseLayout
- Add og:locale (en_GB) + og:locale:alternate (fr_FR, nb_NO) multilingual signals
- Add article:published_time, article:section, article:author on all 5 article pages
- Add Twitter/X summary_large_image card and canonical link on every page
- Generate 13 Jazz Noir branded 1200x630 PNG OG images (satori + resvg-js)
- Add scripts/generate-og-images.mjs + Special Elite font for future regeneration
- Add public/images/articles/ and public/assets/ which were previously untracked

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/assets/schools/usn.svg

@@ -0,0 +1,8 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 480 280">
+  <rect width="480" height="280" rx="28" fill="#08284b"></rect>
+  <rect x="24" y="24" width="432" height="232" rx="22" fill="none" stroke="#c8a85b" stroke-width="2"></rect>
+  <text x="240" y="118" fill="#f7e7bf" font-family="Georgia, serif" font-size="72" font-weight="700" text-anchor="middle">USN</text>
+  <line x1="132" y1="138" x2="348" y2="138" stroke="#c8a85b" stroke-width="2"></line>
+  <text x="240" y="174" fill="#ffffff" font-family="Arial, sans-serif" font-size="18" letter-spacing="2.5" text-anchor="middle">UNIVERSITY OF SOUTH-EASTERN NORWAY</text>
+  <text x="240" y="208" fill="#9eb4d8" font-family="Arial, sans-serif" font-size="15" letter-spacing="5" text-anchor="middle">KONGSBERG</text>
+</svg>