feat(landing): add OG meta tags and image for social sharing

Add Open Graph and Twitter Card meta tags so the landing page shows
a preview image when shared on social platforms.

Author: dinhanhthi

packages/landing/index.html

@@ -4,6 +4,27 @@
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>AI Sync - Synchronize Your AI Configs</title>
+    <meta
+      name="description"
+      content="A central store for CLAUDE.md, .claude, .cursorrules, GEMINI.md and more. Bidirectional sync keeps every repo and machine in lockstep."
+    />
+    <!-- Open Graph -->
+    <meta property="og:type" content="website" />
+    <meta property="og:title" content="AI Sync - Sync Your AI Configs Across All Your Machines" />
+    <meta
+      property="og:description"
+      content="A central store for CLAUDE.md, .claude, .cursorrules, GEMINI.md and more. Bidirectional sync keeps every repo and machine in lockstep."
+    />
+    <meta property="og:image" content="https://ai-sync.dinhanhthi.com/og-image.png" />
+    <meta property="og:url" content="https://ai-sync.dinhanhthi.com" />
+    <!-- Twitter Card -->
+    <meta name="twitter:card" content="summary_large_image" />
+    <meta name="twitter:title" content="AI Sync - Sync Your AI Configs Across All Your Machines" />
+    <meta
+      name="twitter:description"
+      content="A central store for CLAUDE.md, .claude, .cursorrules, GEMINI.md and more. Bidirectional sync keeps every repo and machine in lockstep."
+    />
+    <meta name="twitter:image" content="https://ai-sync.dinhanhthi.com/og-image.png" />
     <link rel="icon" type="image/svg+xml" href="/logo.svg" />
     <link rel="preconnect" href="https://fonts.googleapis.com" />
     <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />