Fix: auto-fix internal links in markdown content for staging

- Add Eleventy transform to automatically prefix internal links with pathPrefix
- Fixes href and src attributes that start with / in HTML output
- Links in markdown files now work correctly in both staging (/preview) and production

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: ManuelColombo

.eleventy.js

@@ -11,6 +11,33 @@ module.exports = function(eleventyConfig) {
   eleventyConfig.addGlobalData("isStaging", process.env.PATH_PREFIX === "/preview");
   eleventyConfig.addGlobalData("pathPrefix", process.env.PATH_PREFIX || "/");
 
+  // Transform: fix internal links in markdown content to work with pathPrefix
+  const pathPrefix = process.env.PATH_PREFIX || "/";
+  if (pathPrefix !== "/") {
+    eleventyConfig.addTransform("fixInternalLinks", function(content) {
+      if (this.page.outputPath && this.page.outputPath.endsWith(".html")) {
+        // Fix href="/..." links (but not href="http...", href="#...", etc)
+        content = content.replace(/href="(\/[^"]*?)"/g, (match, path) => {
+          // Skip external links, anchors, and already prefixed paths
+          if (path.startsWith('http') || path.startsWith('#') || path.startsWith(pathPrefix)) {
+            return match;
+          }
+          return `href="${pathPrefix}${path}"`;
+        });
+
+        // Fix src="/..." for images and scripts
+        content = content.replace(/src="(\/[^"]*?)"/g, (match, path) => {
+          // Skip external resources and already prefixed paths
+          if (path.startsWith('http') || path.startsWith(pathPrefix)) {
+            return match;
+          }
+          return `src="${pathPrefix}${path}"`;
+        });
+      }
+      return content;
+    });
+  }
+
   return {
     dir: {
       input: ".",