Fix all PHPStan level 6 errors

- Add missing use App\Entity\EmailTracking in MailerService
- Add PHPDoc types for array params/returns in MeilisearchService, MeilisearchMessage, ViteAssetExtension
- Remove redundant array_values() in UnsubscribeManager
- Ignore Doctrine-managed $id property warnings in phpstan.neon

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

phpstan.neon

@@ -4,3 +4,10 @@ parameters:
         - src/
     excludePaths:
         - src/Kernel.php
+    ignoreErrors:
+        -
+            message: '#Property App\\Entity\\(EmailTracking|MessengerLog|User)::\$id .* never assigned#'
+            paths:
+                - src/Entity/EmailTracking.php
+                - src/Entity/MessengerLog.php
+                - src/Entity/User.php