Add Open Graph and Twitter Card meta tags for link previews

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: benjaminsnorris

index.html

@@ -4,6 +4,21 @@
   <meta charset="UTF-8">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>SchoolAI STAAR Spaces Directory</title>
+
+  <!-- Open Graph / Social sharing -->
+  <meta property="og:title" content="SchoolAI STAAR Spaces Directory" />
+  <meta property="og:description" content="238 Spaces across all subjects & grades in SchoolAI" />
+  <meta property="og:type" content="website" />
+  <meta property="og:url" content="https://schoolai.github.io/staar-spaces/" />
+
+  <!-- Twitter Card -->
+  <meta name="twitter:card" content="summary" />
+  <meta name="twitter:title" content="SchoolAI STAAR Spaces Directory" />
+  <meta name="twitter:description" content="238 Spaces across all subjects & grades in SchoolAI" />
+
+  <!-- Standard meta description -->
+  <meta name="description" content="238 Spaces across all subjects & grades in SchoolAI" />
+
   <script src="https://cdn.tailwindcss.com"></script>
   <script src="https://unpkg.com/react@18/umd/react.production.min.js" crossorigin></script>
   <script src="https://unpkg.com/react-dom@18/umd/react-dom.production.min.js" crossorigin></script>