Address code review feedback

Narrow closest('a') result with instanceof HTMLAnchorElement for
type safety. Skip non-web protocols (mailto:, tel:, etc.) in
isExternalLinkCandidate to match body-level controller behavior.
Pass element reference to paste_links JS instead of global querySelector.

Author: akabiru

frontend/src/react/extensions/external-link-capture.ts

@@ -63,7 +63,7 @@ export const ExternalLinkCaptureExtension = Extension.create({
                 ? event.target
                 : (event.target as Node)?.parentElement;
               const link = target?.closest('a');
-              if (!link) return false;
+              if (!(link instanceof HTMLAnchorElement)) return false;
               if (!view.dom.contains(link)) return false;
               if (!isExternalLinkCandidate(link)) return false;
               if (!isLinkExternal(link)) return false;

frontend/src/stimulus/helpers/external-link-helpers.ts

@@ -58,12 +58,13 @@ export function isLinkExternal(link:HTMLAnchorElement) {
 
 /**
  * Returns true when the link is eligible for external-link processing.
- * Links with empty hrefs (e.g. anchor-only) and download links are never
- * rewritten or intercepted.
+ * Links with empty hrefs (e.g. anchor-only), download links, and non-web
+ * protocols (mailto:, tel:, javascript:, etc.) are never rewritten or intercepted.
  */
 export function isExternalLinkCandidate(link:HTMLAnchorElement) {
   const href = link.href || '';
   if (href === '' || link.hasAttribute('download')) return false;
+  if (!link.protocol.startsWith('http')) return false;
   return true;
 }
 

spec/support/form_fields/primerized/block_note_editor_input.rb

@@ -59,16 +59,17 @@ def shadow_root
       #     { text: "Two", url: "https://two.com" }
       #   )
       def paste_links(*links)
-        element.click
+        el = element
+        el.click
 
         html = links.map { |l| %(<a href="#{l[:url]}">#{l[:text]}</a>) }.join(" ")
         plain = links.pluck(:text).join(" ")
 
-        page.execute_script(<<~JS, html, plain)
-          const el = document.querySelector('op-block-note').shadowRoot.querySelector('div[role="textbox"]');
+        page.execute_script(<<~JS, el.native, html, plain)
+          const el = arguments[0];
           const dt = new DataTransfer();
-          dt.setData('text/html', arguments[0]);
-          dt.setData('text/plain', arguments[1]);
+          dt.setData('text/html', arguments[1]);
+          dt.setData('text/plain', arguments[2]);
           el.dispatchEvent(new ClipboardEvent('paste', { clipboardData: dt, bubbles: true, cancelable: true }));
         JS
       end