centralize global json-ld in custom head

GEO Optimization: move global schema generation out of Starlight config head
entries and into a dedicated Head component override.

What changed:
- Added `src/components/Head.astro` that composes Starlight default head and
  appends one `application/ld+json` script.
- Kept schema parity for Organization/WebSite/Book and switched Organization
  `@id` to the canonical `swmansion.com` domain.
- Updated `astro.config.ts` to register `components.Head` and removed the
  inline JSON-LD `head` script entry.
- Added AGENTS guidance to assume `Astro.site` is always defined in config.

Why:
- Keeps `astro.config.ts` focused on configuration, not schema object
  construction.
- Creates a stable base for upcoming page-level JSON-LD work while preserving
  existing global graph behavior.

Manual testing:
- Ran `bun lint` (`prettier --write . && astro check`) successfully.
- Ran `bun run build` successfully earlier in this thread and confirmed
  generated HTML still contains the global JSON-LD graph.

Special considerations:
- Commit intentionally includes only staged files from this thread.
- Leaves untracked `GEO.md` untouched.

Author: mkaput

AGENTS.md

@@ -5,3 +5,4 @@
 - you may be running in parallel with other agents; cooperate to avoid conflicts, but avoid committing changes made by others
 - run `bun lint` to format code and run linters (including `astro check`); there are no tests
 - ignore any backward compatibility - break stuff everywhere if needed
+- assume `Astro.site` is always defined in `astro.config.ts`; do not add defensive fallbacks or runtime guards for it

astro.config.ts

@@ -5,48 +5,6 @@ const site = "https://agentic-engineering.swmansion.com/";
 const repo = `https://github.com/software-mansion/agentic-engineering/`;
 const defaultOgImage = `${site}og-default.png`;
 
-const globalJsonLd = JSON.stringify({
-  "@context": "https://schema.org",
-  "@graph": [
-    {
-      "@type": "Organization",
-      "@id": `${site}#organization`,
-      name: "Software Mansion",
-      url: "https://swmansion.com/",
-      logo: {
-        "@type": "ImageObject",
-        url: `${site}swm-logo.png`,
-      },
-    },
-    {
-      "@type": "WebSite",
-      "@id": `${site}#website`,
-      url: site,
-      name: "Software Mansion Agentic Engineering Guide",
-      inLanguage: "en",
-      publisher: {
-        "@id": `${site}#organization`,
-      },
-    },
-    {
-      "@type": "Book",
-      "@id": `${site}#book`,
-      name: "Software Mansion Agentic Engineering Guide",
-      description:
-        "Practical guidance for setting up and scaling agentic engineering workflows in real software projects.",
-      url: site,
-      inLanguage: "en",
-      image: defaultOgImage,
-      publisher: { "@id": `${site}#organization` },
-      author: [
-        { "@type": "Person", name: "Marek Kaput" },
-        { "@type": "Person", name: "Jakub Kosmydel" },
-        { "@type": "Person", name: "Adam Grzybowski" },
-      ],
-    },
-  ],
-});
-
 // https://astro.build/config
 export default defineConfig({
   site,
@@ -102,6 +60,7 @@ export default defineConfig({
         },
       ],
       components: {
+        Head: "./src/components/Head.astro",
         Footer: "./src/components/Footer.astro",
       },
       editLink: {
@@ -129,11 +88,6 @@ export default defineConfig({
           tag: "meta",
           attrs: { name: "twitter:creator", content: "@swmansion" },
         },
-        {
-          tag: "script",
-          attrs: { type: "application/ld+json" },
-          content: globalJsonLd,
-        },
       ],
     }),
   ],

src/components/Head.astro

@@ -0,0 +1,58 @@
+---
+import Default from "@astrojs/starlight/components/Head.astro";
+
+const { lang, siteTitle } = Astro.locals.starlightRoute;
+const organizationId = "https://swmansion.com/#organization";
+const websiteId = new URL("#website", Astro.site);
+const bookId = new URL("#book", Astro.site);
+const defaultOgImage = new URL("og-default.png", Astro.site);
+
+const globalJsonLd = {
+  "@context": "https://schema.org",
+  "@graph": [
+    {
+      "@type": "Organization",
+      "@id": organizationId,
+      name: "Software Mansion",
+      url: "https://swmansion.com/",
+      logo: {
+        "@type": "ImageObject",
+        url: new URL("swm-logo.png", Astro.site),
+      },
+    },
+    {
+      "@type": "WebSite",
+      "@id": websiteId,
+      url: Astro.site,
+      name: siteTitle,
+      inLanguage: lang,
+      publisher: {
+        "@id": organizationId,
+      },
+    },
+    {
+      "@type": "Book",
+      "@id": bookId,
+      name: siteTitle,
+      description:
+        "Practical guidance for setting up and scaling agentic engineering workflows in real software projects.",
+      url: Astro.site,
+      inLanguage: lang,
+      image: defaultOgImage,
+      publisher: { "@id": organizationId },
+      author: [
+        { "@type": "Person", name: "Marek Kaput" },
+        { "@type": "Person", name: "Jakub Kosmydel" },
+        { "@type": "Person", name: "Adam Grzybowski" },
+      ],
+    },
+  ],
+};
+---
+
+<Default />
+<script
+  type="application/ld+json"
+  is:inline
+  set:html={JSON.stringify(globalJsonLd)}
+/>