fix: Task 3 review round 1 - strip control chars before the sanitizer (S32a), S34 minors

Control characters now go on the raw value in AttrWriter::cleanNode and
VariableRef::setting; after the sanitizer only rejection remains ('<' + VT/FF
no longer turns into a tag). VALUE_KEY anchored with D, exact column-width
fractions, nested rows in columns, specialty columns refused, fullwidth by
catalog category, preset ambiguity in DesignSystem::modulePresetId().

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

tests/Unit/Integrations/Divi/Compose/ComposeFixture.php

@@ -111,6 +111,9 @@ final class ComposeFixture
                     12 => ['url' => 'https://kunde.test/wp-content/uploads/halle.jpg', 'alt' => ''],
                     // Alt texts carrying a reference, whole or NUL-split (ruling S33b: dropped).
                     44 => ['url' => 'https://kunde.test/wp-content/uploads/a.jpg', 'alt' => ComposeFixture::REFERENCE_ALT],
+                    // "<" + VT/FF: strip_tags keeps it as text – a later strip would build the tag (S32a).
+                    46 => ['url' => 'https://kunde.test/wp-content/uploads/c.jpg', 'alt' => '<' . chr(11)
+                        . 'img src=x onerror=alert(1)>Team'],
                     45 => ['url' => 'https://kunde.test/wp-content/uploads/b.jpg', 'alt' => '$variable' . chr(0)
                         . substr(ComposeFixture::REFERENCE_ALT, strlen('$variable'))],
                     default => null,