Final adjustments to Daemon <-> Panel communication change

app/Contracts/Repository/DaemonKeyRepositoryInterface.php

@@ -26,6 +26,11 @@ namespace Pterodactyl\Contracts\Repository;
 
 interface DaemonKeyRepositoryInterface extends RepositoryInterface
 {
+    /**
+     * String prepended to keys to identify that they are managed internally and not part of the user API.
+     */
+    const INTERNAL_KEY_IDENTIFIER = 'i_';
+
     /**
      * Gets the daemon keys associated with a specific server.
      *