Landing + support: add Open Graph + Twitter Card meta tags

Pasting keysat.xyz into iMessage / Slack / Discord / X was falling
back to just the <meta name=description> tag (which truncated mid-
sentence and showed no image). Add proper og:* and twitter:* tags so
the share card uses the hero copy + the existing 1024×1024
keysat-thumbnail.png as the social image. Same treatment on support.html
with its own title/description.

Also update the homepage meta description to match the hero copy
verbatim so the on-page lede and the share-card description tell the
same story.

index.html

@@ -4,7 +4,25 @@
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">
 <title>Keysat: Bitcoin-native self-hosted licensing service for software creators</title>
-<meta name="description" content="Keysat is a Bitcoin-native, self-hosted licensing service for software creators. Runs on Start9. Pays in Bitcoin or fiat. Verifies offline. You own the signing key, the customer list, and the payment rails.">
+<meta name="description" content="Keysat is a self-hosted licensing server. Buyers pay you for the software you create, and their license can be verified offline. Your licensing key, customer list, and payment rails all live on your hardware. No SaaS, no middleman, no platform risk.">
+
+<!-- Social sharing (Open Graph + Twitter Card). Used by iMessage,
+     Slack, X/Twitter, Facebook, LinkedIn, Discord, etc. when someone
+     pastes a keysat.xyz link. Description tracks the homepage hero
+     copy so the share card and the landing page tell the same story. -->
+<meta property="og:type" content="website">
+<meta property="og:site_name" content="Keysat">
+<meta property="og:title" content="Keysat: Bitcoin-native self-hosted licensing service for software creators">
+<meta property="og:description" content="Keysat is a self-hosted licensing server. Buyers pay you for the software you create, and their license can be verified offline. Your licensing key, customer list, and payment rails all live on your hardware. No SaaS, no middleman, no platform risk.">
+<meta property="og:url" content="https://keysat.xyz/">
+<meta property="og:image" content="https://keysat.xyz/assets/keysat-thumbnail.png">
+<meta property="og:image:width" content="1024">
+<meta property="og:image:height" content="1024">
+<meta property="og:image:alt" content="Keysat">
+<meta name="twitter:card" content="summary_large_image">
+<meta name="twitter:title" content="Keysat: Bitcoin-native self-hosted licensing service for software creators">
+<meta name="twitter:description" content="Self-hosted licensing for software creators. Buyers pay you for the software you create; licenses verify offline. You own the signing key, the customer list, and the payment rails.">
+<meta name="twitter:image" content="https://keysat.xyz/assets/keysat-thumbnail.png">
 <link rel="icon" type="image/svg+xml" href="assets/favicon.svg">
 
 <link rel="preconnect" href="https://fonts.googleapis.com">

support.html

@@ -5,6 +5,21 @@
 <meta name="viewport" content="width=device-width, initial-scale=1">
 <title>Support Keysat development</title>
 <meta name="description" content="Support Keysat development. Lightning, on-chain, or buy a Patron license.">
+
+<!-- Social sharing (Open Graph + Twitter Card). -->
+<meta property="og:type" content="website">
+<meta property="og:site_name" content="Keysat">
+<meta property="og:title" content="Support Keysat development">
+<meta property="og:description" content="Fund Keysat development directly: Lightning, on-chain Bitcoin, a Patron license, or via OpenSats. Pick whichever fits.">
+<meta property="og:url" content="https://keysat.xyz/support.html">
+<meta property="og:image" content="https://keysat.xyz/assets/keysat-thumbnail.png">
+<meta property="og:image:width" content="1024">
+<meta property="og:image:height" content="1024">
+<meta property="og:image:alt" content="Keysat">
+<meta name="twitter:card" content="summary_large_image">
+<meta name="twitter:title" content="Support Keysat development">
+<meta name="twitter:description" content="Fund Keysat development directly: Lightning, on-chain Bitcoin, a Patron license, or via OpenSats.">
+<meta name="twitter:image" content="https://keysat.xyz/assets/keysat-thumbnail.png">
 <link rel="icon" type="image/svg+xml" href="assets/favicon.svg">
 <link href="https://fonts.googleapis.com/css2?family=Manrope:wght@400;500;600;700;900&family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap" rel="stylesheet">
 <style>