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

src/Integrations/Divi/Design/DesignSystem.php

@@ -4,6 +4,8 @@ declare(strict_types=1);
 
 namespace LIT\MCP\Integrations\Divi\Design;
 
+use InvalidArgumentException;
+
 /**
  * The site's Divi design system as read live from Divi (spec §2 principle 2, §5.7): global
  * colors, global variables, theme fonts and sizes, module and group presets. Pure PHP –
@@ -162,21 +164,40 @@ final class DesignSystem
         return null;
     }
 
-    /** Module preset ID by name or ID for a full module name ("divi/button"); null when unknown. */
+    /**
+     * Module preset ID for a full module name ("divi/button"): an exact ID first, else the one
+     * preset of that name (case-insensitive); null when unknown.
+     *
+     * @throws InvalidArgumentException When several presets of the module share the name (ruling S13a).
+     */
     public function modulePresetId(string $module, string $name): ?string
     {
-        $key = mb_strtolower(trim($name));
+        $wanted = trim($name);
+        $key = mb_strtolower($wanted);
+        $ids = [];
         foreach ($this->presets as $preset) {
-            if (
-                $preset['kind'] === 'module'
-                && $preset['module'] === $module
-                && ($preset['id'] === trim($name) || mb_strtolower($preset['name']) === $key)
-            ) {
+            if ($preset['kind'] !== 'module' || $preset['module'] !== $module) {
+                continue;
+            }
+
+            if ($preset['id'] === $wanted) {
                 return $preset['id'];
             }
+
+            if (mb_strtolower($preset['name']) === $key) {
+                $ids[] = $preset['id'];
+            }
         }
 
-        return null;
+        if (count($ids) > 1) {
+            throw new InvalidArgumentException(sprintf(
+                'Preset-Name "%s" ist mehrdeutig; bitte die ID angeben: %s.',
+                $wanted,
+                implode(', ', $ids)
+            ));
+        }
+
+        return $ids[0] ?? null;
     }
 
     /** @return list<string> Names of the module presets of $module. */