fix: anchor Divi name/id patterns at string end, number-advanced stays unknown, doc wording

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

tests/Unit/Integrations/Divi/BlockTree/BlockTest.php

@@ -19,6 +19,7 @@ final class BlockTest extends TestCase
         return [
             'no namespace' => ['button'],
             'trailing markup injection' => ['divi/x --><script>'],
+            'trailing newline' => ["divi/x\n"],
             'uppercase' => ['Divi/Button'],
             'empty' => [''],
         ];

tests/Unit/Integrations/Divi/BlockTree/NodeIndexTest.php

@@ -42,6 +42,7 @@ final class NodeIndexTest extends TestCase
         );
         self::assertSame(1, preg_match(NodeIndex::ID_PATTERN, 's1.g2'));
         self::assertSame(0, preg_match(NodeIndex::ID_PATTERN, 's1..g2'));
+        self::assertSame(0, preg_match(NodeIndex::ID_PATTERN, "s1\n"));
     }
 
     public function testDocumentWithoutPlaceholderIsItsOwnRoot(): void