relay: custom confirm dialog, custom recipient dropdown, inbox polish

Replaces all native confirm() calls with styled relayConfirm() promise.
Replaces native <select> recipient picker with custom dropdown control.
Adds synced badge, title-only preview, delete-all, inline delete confirm.

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

config.php

@@ -1,7 +1,7 @@
 <?php
 
 define('APP_NAME', 'hyprcrd');
-define('APP_VERSION', '0.9.21');
+define('APP_VERSION', '0.9.22');
 
 // Database path — writable directory, outside webroot
 define('DB_PATH', __DIR__ . '/data/hyprcrd.db');