feat: add share-post.js module for Post buttons

js/share-post.js

@@ -0,0 +1,38 @@
+/**
+ * Share Post — frontend module
+ * Opens the Indiekit share form in a popup window for creating posts
+ * from blogroll, podroll, and news page items.
+ * Only active when user is logged in (body[data-indiekit-auth="true"]).
+ */
+(function () {
+  function isLoggedIn() {
+    return document.body.getAttribute('data-indiekit-auth') === 'true';
+  }
+
+  function openSharePopup(button) {
+    var url = button.dataset.shareUrl;
+    var title = button.dataset.shareTitle || '';
+    var type = button.dataset.shareType || 'note';
+    if (!url) return;
+
+    var shareUrl = '/share/bookmarklet'
+      + '?name=' + encodeURIComponent(title)
+      + '&url=' + encodeURIComponent(url)
+      + '&type=' + encodeURIComponent(type);
+
+    window.open(
+      shareUrl,
+      'Sharer',
+      'resizable,scrollbars,status=0,toolbar=0,menubar=0,titlebar=0,width=578,height=720,location=0'
+    );
+  }
+
+  document.addEventListener('click', function (e) {
+    if (!isLoggedIn()) return;
+    var button = e.target.closest('.share-post-btn');
+    if (button) {
+      e.preventDefault();
+      openSharePopup(button);
+    }
+  });
+})();