refactor: simplify preview generation

Signed-off-by: Sebastian Krupinski <krupinski01@gmail.com>

lib/Manager.php

@@ -5,7 +5,7 @@ declare(strict_types=1);
 namespace KTXM\MailManager;
 
 use InvalidArgumentException;
-use KTXC\Preview\CachedPreview;
+use KTXC\Preview\Preview;
 use KTXC\Preview\PreviewManager;
 use KTXC\Resource\ProviderManager;
 use KTXF\Preview\PreviewSource;
@@ -1359,7 +1359,7 @@ class Manager {
     /**
      * Resolve an authorized attachment and lazily generate or retrieve its preview.
      */
-    public function entityPreview(string $tenantId, string $userId, EntityIdentifier $targetEntity, array $part, string $variant = 'popover'): ?CachedPreview {
+    public function entityPreview(string $tenantId, string $userId, EntityIdentifier $targetEntity, array $part, string $variant = 'popover'): ?Preview {
         $mimeType = $part['type'] ?? null;
         $size = $part['size'] ?? null;
         if (!is_string($mimeType) || ($size !== null && !is_int($size))) {
@@ -1375,9 +1375,11 @@ class Manager {
             throw new InvalidArgumentException('Attachment preview requires a blob, part, or content identifier');
         }
 
+        $attachmentIdentity = hash('sha256', json_encode($selector, JSON_THROW_ON_ERROR));
+
         return $this->previewManager->fetch($tenantId, new PreviewSource(
             sourceType: 'mail-attachment',
-            identity: (string) $targetEntity,
+            identity: (string) $targetEntity . ':' . $attachmentIdentity,
             // Attachments are immutable once delivered, so there is no revision to track;
             // existence and access are enforced by entityDownload() (via serviceFetch) below,
             // which only runs on a cache miss.
@@ -1390,7 +1392,6 @@ class Manager {
                 $targetEntity,
                 $selector,
             ),
-            selector: hash('sha256', json_encode($selector, JSON_THROW_ON_ERROR)),
         ), $variant);
     }