Fix: Assign default messaging tier to new accounts

Author: daveearley

backend/app/Services/Application/Handlers/Account/CreateAccountHandler.php

@@ -66,6 +66,7 @@ public function handle(CreateAccountDTO $accountData): AccountDomainObject
                 'short_id' => IdHelper::shortId(IdHelper::ACCOUNT_PREFIX),
                 'account_verified_at' => $isSaasMode ? null : now()->toDateTimeString(),
                 'account_configuration_id' => $this->getAccountConfigurationId($accountData),
+                'account_messaging_tier_id' => $this->getDefaultMessagingTierId(),
             ]);
 
             $user = $this->getExistingUser($accountData) ?? $this->userRepository->create([
@@ -258,4 +259,10 @@ private function isInternalReferrer(?string $referrer): bool
 
         return $appHost === $referrerHost;
     }
+
+    private function getDefaultMessagingTierId(): int
+    {
+        // Self-hosted instances get Premium tier, SaaS gets Untrusted
+        return $this->config->get('app.is_hi_events') ? 1 : 3;
+    }
 }