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

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);