fix(security): content-create divi follows the Divi group switches (audit M2)

The divi input of lit/content-create is refused with unsupported when
lit/divi-insert is disabled or the Divi group is disabled or read-only
(ExposurePolicy::allows as a cross-group gate, asked at execute time).
content-create without divi keeps working. Adds a registrar test that
read-only write tools are never registered, so execute-ability can't
reach them either.

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

src/Abilities/ExposurePolicy.php

@@ -196,6 +196,24 @@ final class ExposurePolicy
         ));
     }
 
+    /**
+     * Cross-group gate: whether the ability named $name is among $abilities and not disabled.
+     * lit/content-create's divi input follows lit/divi-insert this way (security M2), so the Divi
+     * group's "nur lesen"/disabled switch also stops Divi layouts written through another group.
+     *
+     * @param list<Ability> $abilities
+     */
+    public function allows(string $name, array $abilities): bool
+    {
+        foreach ($abilities as $ability) {
+            if ($ability->name() === $name) {
+                return $this->mode($ability) !== self::DISABLED;
+            }
+        }
+
+        return false;
+    }
+
     /**
      * @param list<Ability> $abilities
      * @return list<string>

src/Integrations/Divi/DiviIntegration.php

@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace LIT\MCP\Integrations\Divi;
 
+use Closure;
 use LIT\MCP\ChangeLog\ChangeLog;
 use LIT\MCP\Integrations\Divi\Design\DesignSystemReader;
 use LIT\MCP\Integrations\Divi\Design\DiviDesignSystemAbility;
@@ -58,14 +59,20 @@ final class DiviIntegration implements Integration
         return DiviModules::isAvailable();
     }
 
-    /** Divi short form for lit/content-create; available() reports whether Divi 5 is loaded. */
-    public function contentComposer(): ContentComposer
+    /**
+     * Divi short form for lit/content-create; available() reports whether Divi 5 is loaded,
+     * writable() asks $writable (the Tools-tab gate, security M2).
+     *
+     * @param (Closure(): bool)|null $writable
+     */
+    public function contentComposer(?Closure $writable = null): ContentComposer
     {
         return new DiviContentComposer(
             $this->schema,
             new DiviComposition($this->modules, $this->design),
             new DiviSaver(),
-            $this->design
+            $this->design,
+            $writable
         );
     }
 

src/Integrations/Divi/Pages/DiviContentComposer.php

@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace LIT\MCP\Integrations\Divi\Pages;
 
+use Closure;
 use LIT\MCP\Abilities\Errors;
 use LIT\MCP\Integrations\Divi\BlockTree\Block;
 use LIT\MCP\Integrations\Divi\BlockTree\Document;
@@ -34,12 +35,18 @@ use WP_Error;
  */
 final class DiviContentComposer implements ContentComposer
 {
+    /** @var Closure(): bool */
+    private Closure $writable;
+
+    /** @param (Closure(): bool)|null $writable Tools-tab gate (Plugin: lit/divi-insert enabled); null = always. */
     public function __construct(
         private ContentSchema $schema,
         private DiviComposition $composition,
         private DiviSaver $saver,
-        private DesignSystemReader $design
+        private DesignSystemReader $design,
+        ?Closure $writable = null
     ) {
+        $this->writable = $writable ?? static fn (): bool => true;
     }
 
     public function available(): bool
@@ -47,6 +54,11 @@ final class DiviContentComposer implements ContentComposer
         return DiviModules::isAvailable();
     }
 
+    public function writable(): bool
+    {
+        return ($this->writable)();
+    }
+
     public function check(string $postType, array $sections): ?WP_Error
     {
         if (! $this->schema->diviEnabled($postType)) {

src/Integrations/WordPress/Content/ContentComposer.php

@@ -21,6 +21,12 @@ interface ContentComposer
     /** Whether composing is possible on this site right now (e.g. Divi 5 active). */
     public function available(): bool;
 
+    /**
+     * Whether the site owner lets LIT MCP write such content (Tools tab: for Divi, lit/divi-insert
+     * is not disabled and the Divi group is neither disabled nor "nur lesen" – security M2).
+     */
+    public function writable(): bool;
+
     /**
      * Validates the description for a new entry of $postType. Nothing is written.
      *

src/Integrations/WordPress/Content/ContentCreateAbility.php

@@ -118,6 +118,15 @@ final class ContentCreateAbility implements Ability
             );
         }
 
+        if ($withDivi && ! $this->divi->writable()) {
+            return Errors::unsupported(
+                'Divi-Inhalte zu schreiben ist in LIT MCP auf dieser Website abgeschaltet; nichts wurde angelegt.',
+                'Die Seite ohne divi anlegen. Divi-Schreiben kann ein Administrator unter Einstellungen → LIT MCP '
+                    . '→ Tools freigeben (Gruppe Divi nicht „nur lesen“ oder deaktiviert, lit-divi-insert nicht '
+                    . 'deaktiviert).'
+            );
+        }
+
         $prepared = $this->writer->prepare($postType, $input, true);
         $problem = self::combined($prepared, $withDivi ? $this->checkDivi($postType, $input) : null);
         if ($problem !== null) {

src/Plugin.php

@@ -68,9 +68,18 @@ final class Plugin
 
         $schema = self::contentSchema();
         $divi = new DiviIntegration($schema, $changeLog);
+        $registry = null;
+        $policy = null;
+        // Security M2: content-create's divi input follows lit/divi-insert (asked at execute time,
+        // when registry and policy exist), so the Divi group's switches stop every Divi layout write.
+        $diviWritable = static function () use (&$registry, &$policy): bool {
+            return $registry instanceof IntegrationRegistry
+                && $policy instanceof ExposurePolicy
+                && $policy->allows('lit/divi-insert', $registry->abilities());
+        };
         $registry = new IntegrationRegistry(
             new CoreIntegration(self::pluginDir() . '/docs/guides'),
-            new WordPressIntegration($schema, $changeLog, $divi->contentComposer()),
+            new WordPressIntegration($schema, $changeLog, $divi->contentComposer($diviWritable)),
             new MediaIntegration($schema, $changeLog, $limits),
             $divi
         );

tests/Unit/Abilities/AbilityRegistrarTest.php

@@ -236,4 +236,28 @@ final class AbilityRegistrarTest extends TestCase
         (new AbilityRegistrar($registry, (new ExposurePolicy(['@group:divi' => 'disabled']))->withGroups($registry->groupMap())))
             ->registerAbilities();
     }
+
+    /**
+     * Security M2 follow-up: a write tool of a "nur lesen" group is never registered, so
+     * mcp-adapter-execute-ability cannot reach it either (it resolves abilities via
+     * wp_get_ability()); the group's read tools stay.
+     */
+    public function testReadonlyGroupWriteAbilitiesAreNotRegisteredForExecuteAbilityEither(): void
+    {
+        $write = Mockery::mock(Ability::class);
+        $write->allows('name')->andReturn('lit/divi-insert');
+        $write->allows('isDirect')->andReturn(true);
+        $write->allows('annotations')->andReturn(['readonly' => false]);
+        $read = $this->ability();
+        $read->allows('name')->andReturn('lit/test');
+        $integration = Mockery::mock(Integration::class);
+        $integration->allows('id')->andReturn('divi');
+        $integration->allows('isAvailable')->andReturn(true);
+        $integration->allows('abilities')->andReturn([$write, $read]);
+        $registry = new IntegrationRegistry($integration);
+        Functions\expect('wp_register_ability')->once()->with('lit/test', Mockery::type('array'));
+
+        (new AbilityRegistrar($registry, (new ExposurePolicy(['@readonly:divi' => true]))->withGroups($registry->groupMap())))
+            ->registerAbilities();
+    }
 }

tests/Unit/Abilities/ExposurePolicyTest.php

@@ -124,6 +124,7 @@ final class ExposurePolicyTest extends TestCase
         'lit/divi-outline' => 'divi',
         'lit/divi-update' => 'divi',
         'lit/divi-delete' => 'divi',
+        'lit/divi-insert' => 'divi',
         'lit/media-preview' => 'media',
         'lit/media-download' => 'media',
         'lit/media-get' => 'media',
@@ -282,4 +283,32 @@ final class ExposurePolicyTest extends TestCase
         self::assertSame('direct', $policy->mode($this->ability('lit/site-status', true)));
         self::assertSame(1, $calls);
     }
+
+    /**
+     * Cross-group gate (security M2): lit/content-create's divi input follows lit/divi-insert – off
+     * when that tool is disabled, its group is disabled or "nur lesen", or it does not exist.
+     */
+    public function testAllowsFollowsTheNamedAbilitysMode(): void
+    {
+        $insert = $this->ability('lit/divi-insert', true, ['readonly' => false]);
+        $others = [$this->ability('lit/divi-outline', true, ['readonly' => true]), $insert];
+
+        self::assertTrue((new ExposurePolicy())->withGroups(self::GROUPS)->allows('lit/divi-insert', $others));
+        self::assertTrue(
+            (new ExposurePolicy(['lit/divi-insert' => 'indirect']))->allows('lit/divi-insert', $others),
+            'indirect still writes'
+        );
+        foreach (
+            [
+                ['lit/divi-insert' => 'disabled'],
+                ['@group:divi' => 'disabled'],
+                ['@readonly:divi' => true, 'lit/divi-insert' => 'direct'],
+            ] as $option
+        ) {
+            $policy = (new ExposurePolicy($option))->withGroups(self::GROUPS);
+            self::assertFalse($policy->allows('lit/divi-insert', $others), (string) json_encode($option));
+        }
+
+        self::assertFalse((new ExposurePolicy())->allows('lit/divi-insert', []), 'Divi not available');
+    }
 }

tests/Unit/Integrations/Divi/Pages/DiviContentComposerTest.php

@@ -142,4 +142,19 @@ final class DiviContentComposerTest extends TestCase
         $this->expectException(RuntimeException::class);
         $this->composer()->write(42, 'page', self::sections());
     }
+
+    public function testWritableFollowsTheGateAndDefaultsToTrue(): void
+    {
+        self::assertTrue($this->composer()->writable());
+
+        $design = DiviWriterFixture::designReader();
+        $gated = new DiviContentComposer(
+            DiviFixtures::schema(true),
+            DiviWriterFixture::composition($design),
+            $this->saver,
+            $design,
+            static fn (): bool => false
+        );
+        self::assertFalse($gated->writable());
+    }
 }

tests/Unit/Integrations/WordPress/Content/ContentCreateDiviTest.php

@@ -56,10 +56,11 @@ final class ContentCreateDiviTest extends TestCase
     }
 
     /** @return ContentComposer&MockInterface */
-    private function composer(bool $available = true): ContentComposer
+    private function composer(bool $available = true, bool $writable = true): ContentComposer
     {
         $composer = Mockery::mock(ContentComposer::class);
         $composer->allows('available')->andReturn($available);
+        $composer->allows('writable')->andReturn($writable);
         $composer->allows('check')->with('page', self::SECTIONS)->andReturn(null);
 
         return $composer;
@@ -139,11 +140,39 @@ final class ContentCreateDiviTest extends TestCase
         self::assertArrayHasKey('content', self::errorFields($both));
     }
 
+    /**
+     * Security M2: with the Divi group disabled or "nur lesen", or lit/divi-insert disabled, the
+     * divi input is refused before anything is created; content-create without divi keeps working.
+     */
+    public function testDiviIsRefusedWhenDiviWritesAreSwitchedOff(): void
+    {
+        Functions\expect('wp_insert_post')->never();
+
+        $error = $this->ability($this->composer(true, false))->execute(self::INPUT);
+
+        $payload = self::assertToolError($error, 'unsupported');
+        self::assertStringContainsString('Tools', (string) $payload['hint']);
+        self::assertStringContainsString('ohne divi', (string) $payload['hint']);
+    }
+
+    public function testWithoutDiviTheGateIsNotAsked(): void
+    {
+        $composer = Mockery::mock(ContentComposer::class);
+        $composer->expects('writable')->never();
+        Functions\when('wp_insert_post')->justReturn(42);
+        $this->stubStoredDraft();
+
+        $result = $this->ability($composer)->execute(['post_type' => 'page', 'title' => 'Start']);
+
+        self::assertTrue($result['ok']);
+    }
+
     public function testEveryValidationErrorComesBackAndNothingIsCreated(): void
     {
         Functions\expect('wp_insert_post')->never();
         $composer = Mockery::mock(ContentComposer::class);
         $composer->allows('available')->andReturn(true);
+        $composer->allows('writable')->andReturn(true);
         $composer->allows('check')->andReturn(Errors::invalidAttrPath(['divi[0].attrs.x' => 'unbekannt']));
         $writer = Mockery::mock(PostWriter::class);
         $writer->allows('prepare')->andReturn(Errors::invalidInput('ungültig', ['fields.role' => 'Pflichtfeld fehlt.']));
@@ -238,6 +267,11 @@ final class ContentCreateDiviTest extends TestCase
                 return true;
             }
 
+            public function writable(): bool
+            {
+                return true;
+            }
+
             public function check(string $postType, array $sections): ?WP_Error
             {
                 return $this->real->check($postType, $sections);