fix(seo): sync meta tags, robots.txt and sitemap config from samber/do

- Add twitter:site, og:locale, og:site_name head tags
- Add fallback description meta tag
- Exclude /search from sitemap
- Disallow /search and /tags/ in robots.txt

docs/docusaurus.config.ts

@@ -135,9 +135,35 @@ const config: Config = {
         content: '@samuelberthe',
       },
     },
-    // NOTE: do not add a global <link rel="canonical"> here.
-    // Docusaurus generates correct per-page canonical tags from the `url` field above.
-    // A global canonical in headTags applies to ALL pages and conflicts with those.
+    // twitter:site complements twitter:creator for card attribution
+    {
+      tagName: 'meta',
+      attributes: {
+        name: 'twitter:site',
+        content: '@samuelberthe',
+      },
+    },
+    // og:locale signals language/region to crawlers and social platforms
+    {
+      tagName: 'meta',
+      attributes: {
+        property: 'og:locale',
+        content: 'en_US',
+      },
+    },
+    // og:site_name provides branding context in social share cards
+    {
+      tagName: 'meta',
+      attributes: {
+        property: 'og:site_name',
+        content: 'samber/lo',
+      },
+    },
+    // NOTE: do NOT add a global <link rel="canonical"> here.
+    // Docusaurus injects a correct per-page canonical automatically
+    // based on `url` + `baseUrl` + the page path. A static href here
+    // would override every page's canonical to the homepage, causing
+    // Google to treat all docs pages as non-canonical duplicates.
   ],
 
   customFields: {
@@ -181,7 +207,7 @@ const config: Config = {
           lastmod: 'date',
           changefreq: 'weekly',
           priority: 0.7,
-          ignorePatterns: ['/tags/**'],
+          ignorePatterns: ['/tags/**', '/search'],
           filename: 'sitemap.xml',
           // Enhanced sitemap features from 3.8+
           createSitemapItems: async (params) => {
@@ -228,8 +254,12 @@ const config: Config = {
     },
 
       // Enhanced metadata
+    // og:type defaults to "website"; individual doc pages that need
+    // "article" should override via their page's <Layout> or frontmatter.
     metadata: [
       {name: 'og:type', content: 'website'},
+      // Fallback description for pages that don't set their own
+      {name: 'description', content: 'A Lodash-style utility library for Go. Slices, maps, channels, and more — type-safe, using generics.'},
     ],
 
     navbar: {

docs/static/robots.txt

@@ -1,4 +1,8 @@
 User-agent: *
 Allow: /
 
+# Low-value pages — no need to crawl or index
+Disallow: /search
+Disallow: /tags/
+
 Sitemap: https://lo.samber.dev/sitemap.xml