fix: convert Date objects to ISO strings for blog edit items

The Indiekit date filter calls parseISO() which expects a string.
MongoDB returns Date objects for item.published, causing
"dateString.split is not a function" error on the blog edit page.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/controllers/blogs.js

@@ -157,7 +157,14 @@ async function edit(request, response) {
       return response.status(404).render("404");
     }
 
-    const items = await getItemsForBlog(application, blog._id, 10);
+    const rawItems = await getItemsForBlog(application, blog._id, 10);
+    const items = rawItems.map((item) => ({
+      ...item,
+      published:
+        item.published instanceof Date
+          ? item.published.toISOString()
+          : item.published,
+    }));
 
     response.render("blogroll-blog-edit", {
       title: request.__("blogroll.blogs.edit"),

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@rmdes/indiekit-endpoint-blogroll",
-  "version": "1.0.8",
+  "version": "1.0.9",
   "description": "Blogroll endpoint for Indiekit. Aggregates blog feeds from OPML, JSON feeds, or manual entry.",
   "keywords": [
     "indiekit",