feat: structure and content fingerprints, lit/library-find-similar

Fingerprint::structure()/content() (E11) and lit/library-find-similar
(indirect, group Divi-Bibliothek): at most 200 posts per call (cursor),
editable entries only (own posts without edit_others_posts), contents
primed in chunks of 50, stops at 200 matches or 5000 compared nodes with
a note; library entries and Theme Builder layouts are never scanned.

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

src/Integrations/Divi/DiviIntegration.php

@@ -168,7 +168,8 @@ final class DiviIntegration implements Integration
             new DiviSaver(),
             $this->log,
             $this->modules,
-            $this->diviWritable
+            $this->diviWritable,
+            $this->schema
         );
     }