Fix ComponentGroup location/reference to match Nuxt module conventions

The module looks up component groups by reference = "{slot}_{ownerIri}"
and sets location = ownerIri when auto-creating groups. Fixture-created
groups must use the same format so the module finds and renders them
instead of creating new empty groups over the top.

Author: silverbackdan

src/Fixture/CwaFixtureBuilder.php

@@ -296,14 +296,11 @@ private function phaseOne(): void
 
     private function createAndLinkComponentGroup(GroupBuilder $groupBuilder, Layout|Page $owner): void
     {
-        $componentGroup = new ComponentGroup();
-        $componentGroup->location = $groupBuilder->getName();
+        $ownerIri = $this->iriConverter->getIriFromResource($owner);
 
-        if ($owner instanceof Layout) {
-            $componentGroup->reference = \sprintf('layout:%s/%s', $owner->reference, $groupBuilder->getName());
-        } else {
-            $componentGroup->reference = \sprintf('page:%s/%s', $owner->reference ?? $owner->getTitle(), $groupBuilder->getName());
-        }
+        $componentGroup = new ComponentGroup();
+        $componentGroup->location = $ownerIri;
+        $componentGroup->reference = $groupBuilder->getName() . '_' . $ownerIri;
 
         foreach ($groupBuilder->getAllowedClasses() as $class) {
             $componentGroup->addAllowedComponent(
@@ -318,6 +315,12 @@ private function createAndLinkComponentGroup(GroupBuilder $groupBuilder, Layout|
         $this->timestampedPersister->persistTimestampedFields($componentGroup, true);
         // Add to the owning side BEFORE the first flush so Doctrine writes the join table.
         $owner->getComponentGroups()->add($componentGroup);
+        // Sync the inverse side for in-memory consistency (Doctrine populates it from DB on load).
+        if ($owner instanceof Layout) {
+            $componentGroup->layouts->add($owner);
+        } else {
+            $componentGroup->pages->add($owner);
+        }
         $this->componentGroupMap[spl_object_id($groupBuilder)] = $componentGroup;
         $this->manager->persist($componentGroup);
     }

tests/Fixture/CwaFixtureBuilderTest.php

@@ -170,7 +170,9 @@ public function test_layout_group_creates_component_group_with_correct_propertie
         $em = $this->collectingEm($persisted);
 
         $iriConverter = $this->createStub(IriConverterInterface::class);
-        $iriConverter->method('getIriFromResource')->willReturn('/_/some_components'); // any call returns the stub IRI
+        $iriConverter->method('getIriFromResource')->willReturnCallback(
+            static fn ($resource) => is_string($resource) ? '/_/some_components' : '/_api/_/layouts/test-uuid'
+        );
 
         $builder = $this->makeBuilder($em, iriConverter: $iriConverter);
         $builder->layout('main', 'CwaLayoutPrimary')->group('nav', allow: [\stdClass::class]);
@@ -180,8 +182,8 @@ public function test_layout_group_creates_component_group_with_correct_propertie
         $layouts = array_values(array_filter($persisted, static fn ($e) => $e instanceof Layout));
 
         $this->assertCount(1, $groups);
-        $this->assertSame('layout:main/nav', $groups[0]->reference);
-        $this->assertSame('nav', $groups[0]->location);
+        $this->assertSame('nav_/_api/_/layouts/test-uuid', $groups[0]->reference);
+        $this->assertSame('/_api/_/layouts/test-uuid', $groups[0]->location);
         $this->assertSame(['/_/some_components'], $groups[0]->allowedComponents);
 
         $this->assertCount(1, $layouts);
@@ -196,7 +198,10 @@ public function test_page_group_creates_component_group_linked_to_page(): void
         $persisted = [];
         $em = $this->collectingEm($persisted);
 
-        $builder = $this->makeBuilder($em);
+        $iriConverter = $this->createStub(IriConverterInterface::class);
+        $iriConverter->method('getIriFromResource')->willReturn('/_api/_/pages/test-uuid');
+
+        $builder = $this->makeBuilder($em, iriConverter: $iriConverter);
         $builder->layout('main', 'CwaLayoutPrimary');
         $builder->page('home', 'PrimaryPageTemplate', layout: 'main', isTemplate: true)
             ->group('primary');
@@ -206,8 +211,8 @@ public function test_page_group_creates_component_group_linked_to_page(): void
         $pages = array_values(array_filter($persisted, static fn ($e) => $e instanceof Page));
 
         $this->assertCount(1, $groups);
-        $this->assertSame('page:home/primary', $groups[0]->reference);
-        $this->assertSame('primary', $groups[0]->location);
+        $this->assertSame('primary_/_api/_/pages/test-uuid', $groups[0]->reference);
+        $this->assertSame('/_api/_/pages/test-uuid', $groups[0]->location);
         $this->assertNull($groups[0]->allowedComponents);
 
         $this->assertCount(1, $pages);