fix: link targets never reveal library entries by type (ruling Q14)

WpLinkTargets answers the library, internal "_" types and every type
without a Divi post_link_url option like a missing ID; replace-text strips
library IDs only from global subtrees.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/Integrations/Divi/Pages/WpLinkTargets.php

@@ -4,32 +4,62 @@ declare(strict_types=1);
 
 namespace LIT\MCP\Integrations\Divi\Pages;
 
+use Closure;
 use LIT\MCP\Integrations\Divi\Compose\LinkTargets;
 use WP_Post;
 
 defined('ABSPATH') || exit;
 
 /**
- * {{link:<ID>}} and post_link_url_* targets from WordPress (ruling P10): the entry exists, lives
- * (no trash, auto-draft or revision), is no attachment (whatever its status) and the current user
- * may read it (read_post, like select_post settings, S37). Missing and unreadable entries give the
- * same null (no existence oracle).
+ * {{link:<ID>}} and post_link_url_* targets from WordPress (rulings P10, Q14): the entry exists,
+ * lives (no trash, auto-draft or revision), is no attachment (whatever its status), its type has a
+ * Divi link option post_link_url_<type> (never the library et_pb_layout or an internal "_" type) and
+ * the current user may read it (read_post, like select_post settings, S37). Missing, unreadable and
+ * unlinkable entries give the same null (no existence or type oracle).
  */
 final class WpLinkTargets implements LinkTargets
 {
     private const DEAD = ['trash', 'auto-draft', 'inherit'];
 
+    /** Never link targets, whatever Divi lists: attachments and the Divi Library (ruling Q14). */
+    private const NEVER = ['attachment', 'et_pb_layout'];
+
+    /** @var Closure(string): bool */
+    private Closure $linkable;
+
+    /**
+     * @param (Closure(string): bool)|null $linkable Whether Divi offers post_link_url_<type> (tests);
+     *        null = Divi's et_builder_get_public_post_types(), the list its link option uses.
+     */
+    public function __construct(?Closure $linkable = null)
+    {
+        $this->linkable = $linkable ?? self::diviLinkable(...);
+    }
+
     public function postTypeOf(int $id): ?string
     {
         $post = get_post($id);
-        if (
-            ! $post instanceof WP_Post
-            || in_array((string) $post->post_status, self::DEAD, true)
-            || $post->post_type === 'attachment'
-        ) {
+        if (! $post instanceof WP_Post || in_array((string) $post->post_status, self::DEAD, true)) {
             return null;
         }
 
-        return current_user_can('read_post', $id) ? (string) $post->post_type : null;
+        $type = (string) $post->post_type;
+        if (in_array($type, self::NEVER, true) || str_starts_with($type, '_') || ! ($this->linkable)($type)) {
+            return null;
+        }
+
+        return current_user_can('read_post', $id) ? $type : null;
+    }
+
+    /** Fail closed: without Divi's list no type has a link option. */
+    private static function diviLinkable(string $type): bool
+    {
+        if (! function_exists('et_builder_get_public_post_types')) {
+            return false;
+        }
+
+        $types = et_builder_get_public_post_types();
+
+        return is_array($types) && array_key_exists($type, $types);
     }
 }