fix(seo): correct canonical tags and localized blog post hreflang

lib/blog.ts

@@ -136,6 +136,60 @@ export async function getPostBySlug(slug: string, locale: string): Promise<PostD
   }
 }
 
+export async function getPostSlugs(slug: string, locale: string): Promise<Record<string, string>> {
+  try {
+    const payload = await getPayload({ config: configPromise });
+
+    // First, find the post in the current locale to get its ID
+    let { docs } = await payload.find({
+      collection: 'posts',
+      where: {
+        slug: { equals: slug },
+        ...(!config.showDrafts ? { _status: { equals: 'published' } } : {}),
+      },
+      locale: locale as any,
+      draft: config.showDrafts,
+      limit: 1,
+    });
+
+    if (!docs || docs.length === 0) {
+      // Fallback: search across all locales
+      const { docs: crossLocaleDocs } = await payload.find({
+        collection: 'posts',
+        where: {
+          slug: { equals: slug },
+          ...(!config.showDrafts ? { _status: { equals: 'published' } } : {}),
+        },
+        locale: 'all',
+        draft: config.showDrafts,
+        limit: 1,
+      });
+      docs = crossLocaleDocs;
+    }
+
+    if (!docs || docs.length === 0) return {};
+
+    const postId = docs[0].id;
+
+    // Fetch the post with locale 'all' to get all localized fields
+    const { docs: allLocalesDocs } = await payload.find({
+      collection: 'posts',
+      where: {
+        id: { equals: postId },
+      },
+      locale: 'all',
+      draft: config.showDrafts,
+      limit: 1,
+    });
+
+    if (!allLocalesDocs || allLocalesDocs.length === 0) return {};
+    return (allLocalesDocs[0].slug as unknown as Record<string, string>) || {};
+  } catch (error) {
+    console.error(`[Payload] getPostSlugs failed for ${slug}:`, error);
+    return {};
+  }
+}
+
 export async function getAllPosts(locale: string): Promise<PostData[]> {
   try {
     const payload = await getPayload({ config: configPromise });