feat: add Open Graph and Twitter Card meta tags for social sharing

layouts/_default/baseof.html

@@ -6,6 +6,8 @@
   <meta name="description" content="{{ if .Description }}{{ .Description }}{{ else }}{{ .Site.Params.description }}{{ end }}">
   <title>{{ if .IsHome }}{{ .Site.Title }}{{ else }}{{ .Title }} | {{ .Site.Title }}{{ end }}</title>
 
+  {{ partial "opengraph.html" . }}
+
   <!-- Bootstrap 5.x CSS -->
   <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-T3c6CoIi6uLrA9TneNEoa7RxnatzjcDSCmG1MXxSR1GAsXEV/Dwwykc2MPK8M2HN" crossorigin="anonymous">
 

layouts/partials/opengraph.html

@@ -0,0 +1,32 @@
+{{/* Open Graph / Social Media Meta Tags */}}
+
+{{/* Basic OG tags */}}
+<meta property="og:title" content="{{ .Title }}">
+<meta property="og:description" content="{{ with .Description }}{{ . }}{{ else }}{{ with .Site.Params.description }}{{ . }}{{ end }}{{ end }}">
+<meta property="og:url" content="{{ .Permalink }}">
+<meta property="og:type" content="{{ if .IsPage }}article{{ else }}website{{ end }}">
+<meta property="og:site_name" content="{{ .Site.Title }}">
+<meta property="og:locale" content="{{ .Language.Lang }}">
+
+{{/* Article-specific tags */}}
+{{ if .IsPage }}
+<meta property="article:published_time" content="{{ .Date.Format "2006-01-02T15:04:05Z07:00" }}">
+{{ with .Lastmod }}<meta property="article:modified_time" content="{{ .Format "2006-01-02T15:04:05Z07:00" }}">{{ end }}
+{{ end }}
+
+{{/* Image handling: only render if images defined in frontmatter */}}
+{{ with .Params.images }}
+  {{ range first 1 . }}
+    {{ $img := . }}
+    {{ if not (hasPrefix $img "http") }}
+      {{ $img = printf "%s%s" $.Permalink $img }}
+    {{ end }}
+    <meta property="og:image" content="{{ $img }}">
+    <meta name="twitter:image" content="{{ $img }}">
+  {{ end }}
+{{ end }}
+
+{{/* Twitter Card */}}
+<meta name="twitter:card" content="summary_large_image">
+<meta name="twitter:title" content="{{ .Title }}">
+<meta name="twitter:description" content="{{ with .Description }}{{ . }}{{ else }}{{ with .Site.Params.description }}{{ . }}{{ end }}{{ end }}">