perf(relationships): drop Attribute::fromDocument allocation in hot loops

afterDocumentCreate/Update and populateDocuments each instantiated a
new Attribute object per relationship per call just to read .key (and
sometimes .type), which the underlying Document already exposes via
getAttribute(). For populateDocuments specifically this fired on every
relationship across every batch traversal at every depth.

Replace with direct getAttribute('key', $relationship->getId()) and
the existing Attribute::isRelationship static helper.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: abnegate

src/Database/Hook/Relationships.php

@@ -143,8 +143,8 @@ public function afterDocumentCreate(Document $collection, Document $document): D
         $stackCount = \count($this->writeStack);
 
         foreach ($relationships as $relationship) {
-            $typedRelAttr = Attribute::fromDocument($relationship);
-            $key = $typedRelAttr->key;
+            /** @var string $key */
+            $key = $relationship->getAttribute('key', $relationship->getId());
             $value = $document->getAttribute($key);
             $rel = RelationshipVO::fromDocument($collection->getId(), $relationship);
             $relatedCollection = $this->db->getCollection($rel->relatedCollection);
@@ -293,8 +293,8 @@ public function afterDocumentUpdate(Document $collection, Document $old, Documen
         $stackCount = \count($this->writeStack);
 
         foreach ($relationships as $index => $relationship) {
-            $typedRelAttr = Attribute::fromDocument($relationship);
-            $key = $typedRelAttr->key;
+            /** @var string $key */
+            $key = $relationship->getAttribute('key', $relationship->getId());
             $value = $document->getAttribute($key);
 
             $value = $this->coerceToDocument($document, $key, $value);
@@ -819,21 +819,28 @@ public function populateDocuments(array $documents, Document $collection, int $f
                     $relationships = [];
 
                     foreach ($popAttributes as $attribute) {
-                        $typedPopAttr = Attribute::fromDocument($attribute);
-                        if ($typedPopAttr->type === ColumnType::Relationship) {
-                            if ($typedPopAttr->key === $skipKey) {
-                                continue;
-                            }
+                        // Avoid the Attribute::fromDocument allocation —
+                        // we only need the type and key here, both of
+                        // which are plain Document attributes.
+                        if (! Attribute::isRelationship($attribute)) {
+                            continue;
+                        }
 
-                            if (! $parentHasExplicitSelects || \array_key_exists($typedPopAttr->key, $sels)) {
-                                $relationships[] = $attribute;
-                            }
+                        /** @var string $popKey */
+                        $popKey = $attribute->getAttribute('key', $attribute->getId());
+
+                        if ($popKey === $skipKey) {
+                            continue;
+                        }
+
+                        if (! $parentHasExplicitSelects || \array_key_exists($popKey, $sels)) {
+                            $relationships[] = $attribute;
                         }
                     }
 
                     foreach ($relationships as $relationship) {
-                        $typedRelAttr = Attribute::fromDocument($relationship);
-                        $key = $typedRelAttr->key;
+                        /** @var string $key */
+                        $key = $relationship->getAttribute('key', $relationship->getId());
                         $queries = $sels[$key] ?? [];
                         $relationship->setAttribute('collection', $coll->getId());
                         $isAtMaxDepth = ($currentDepth + 1) >= Database::RELATION_MAX_DEPTH;