Convert breadcrumb list items to a plain array before encoding

spatie/schema-org's serializeProperty() only recurses into PHP arrays,
so the Laravel Collection passed to itemListElement() got coerced via
__toString() into a JSON string. That left BreadcrumbList with a
stringified itemListElement and per-item @context, which Search Console
flagged as invalid (#215). Calling ->all() lets serializeProperty
recurse normally and strip the nested @context.

Author: aerni

src/Cascades/ContentCascade.php

@@ -233,7 +233,8 @@ public function breadcrumbs(): ?string
             ->map(fn ($crumb) => Schema::listItem()
                 ->position($crumb['position'])
                 ->name($crumb['title'])
-                ->item($crumb['url']));
+                ->item($crumb['url']))
+            ->all();
 
         return json_encode(
             Schema::breadcrumbList()->itemListElement($listItems),

tests/Cascades/ContentCascadeTest.php

@@ -332,7 +332,14 @@
 
     $breadcrumbs = json_decode($this->cascade->breadcrumbs(), true);
 
-    expect($breadcrumbs['@type'])->toBe('BreadcrumbList');
+    expect($breadcrumbs['@context'])->toBe('https://schema.org')
+        ->and($breadcrumbs['@type'])->toBe('BreadcrumbList')
+        ->and($breadcrumbs['itemListElement'])->toBeArray();
+
+    foreach ($breadcrumbs['itemListElement'] as $item) {
+        expect($item)->not->toHaveKey('@context')
+            ->and($item['@type'])->toBe('ListItem');
+    }
 });
 
 it('returns null page schema when json ld is not set', function () {