Wire admin studio SSR and search infrastructure

app/Services/Sitemaps/Builders/AbstractIdShardableSitemapBuilder.php

@@ -35,10 +35,7 @@ abstract class AbstractIdShardableSitemapBuilder extends AbstractSitemapBuilder
 
     public function lastModified(): ?DateTimeInterface
     {
-        return $this->newest(...array_map(
-            fn (SitemapUrl $item): ?DateTimeInterface => $item->lastModified,
-            $this->items(),
-        ));
+        return $this->dateTime((clone $this->query())->max($this->lastModifiedColumn()));
     }
 
     public function totalItems(): int
@@ -69,10 +66,16 @@ abstract class AbstractIdShardableSitemapBuilder extends AbstractSitemapBuilder
 
     public function lastModifiedForShard(int $shard): ?DateTimeInterface
     {
-        return $this->newest(...array_map(
-            fn (SitemapUrl $item): ?DateTimeInterface => $item->lastModified,
-            $this->itemsForShard($shard),
-        ));
+        $window = $this->shardWindow($shard);
+
+        if ($window === null) {
+            return null;
+        }
+
+        return $this->dateTime(
+            $this->applyShardWindow($window['from'], $window['to'])
+                ->max($this->lastModifiedColumn()),
+        );
     }
 
     /**
@@ -132,4 +135,9 @@ abstract class AbstractIdShardableSitemapBuilder extends AbstractSitemapBuilder
     {
         return $this->idColumn();
     }
+
+    protected function lastModifiedColumn(): string
+    {
+        return 'updated_at';
+    }
 }