fix: identical means identical bytes – text parts count, pages and posts only (ruling Q25)

- Fingerprint::content() includes non-whitespace text parts (raw HTML between
  blocks, inner HTML of core blocks) and opaque blocks with all their bytes;
  structure() unchanged; find-similar "identical" follows
- make-global mode 2 also compares Fingerprint::canonical() bytes of each node
- sources and targets: post types page and post only (POST_TYPES)
- a rolled-back page N>1 keeps DiviSaver's "Revision X bleibt erhalten"
- guide: escaped divi/global-layout re-expanded by Divi's do_blocks in
  shortcode-module and WooCommerce text output documented as residual risk

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7

tests/Unit/Integrations/Divi/Library/LibraryFindSimilarAbilityTest.php

@@ -212,4 +212,33 @@ final class LibraryFindSimilarAbilityTest extends TestCase
         self::assertCount(5, $rest['matches']);
         self::assertArrayNotHasKey('note', $rest);
     }
+
+    /** Ruling Q25: raw HTML next to the blocks is visible – such a copy is only "structure", never "identical". */
+    public function testExtraVisibleTextIsNotIdentical(): void
+    {
+        $root = LibraryContent::roots(LibraryContent::load(
+            new Parser(),
+            DiviFixtures::markup('stage3/library--library-abschnitt.html')
+        ))[0];
+        $copy = Serializer::block($root);
+        $at = strrpos($copy, '<!-- /wp:divi/column -->');
+        $changed = substr($copy, 0, (int) $at) . '<p>ONLY ON 8</p>' . substr($copy, (int) $at);
+        LibraryFixtures::given([
+            LibraryFixtures::item(1055),
+            new WP_Post(['ID' => 8, 'post_type' => 'page', 'post_status' => 'publish', 'post_title' => 'Über uns',
+                'post_content' => '<!-- wp:divi/placeholder -->' . $changed . '<!-- /wp:divi/placeholder -->']),
+        ]);
+        Functions\when('get_post_type_object')->justReturn((object) ['cap' => (object) [
+            'edit_posts' => 'edit_posts',
+            'edit_others_posts' => 'edit_others_posts',
+        ]]);
+        Functions\when('get_posts')->justReturn([8]);
+
+        $result = self::ability()->execute(['library_id' => 1055, 'post_type' => 'page']);
+
+        self::assertSame(['8 s0 structure'], array_map(
+            static fn (array $m): string => $m['post_id'] . ' ' . $m['id'] . ' ' . $m['match'],
+            $result['matches']
+        ));
+    }
 }