feat: domains, transports, logs, quarantine, spam filter, i18n + UX fixes

Features added:
- Admin > Domains: add domains to Mailcow servers, auto-generate DKIM,
  display full DNS record set (MX, SPF, DMARC, DKIM, autoconfig CNAMEs)
  with one-click copy per record
- Admin > Transports: manage sender-dependent relay hosts (add/delete)
- Admin > Logs: view Postfix, Dovecot, Rspamd, Ratelimit, API and other
  server logs in a dark scrollable panel
- My Account: per-domain Quarantine panel — view score, sender, subject,
  date; permanently delete quarantined messages
- My Account: per-mailbox Spam Filter slider (1–15 threshold) saved via API
- My Account: Aliases & Forwarders (alias creation doubles as forwarder
  to any external address)

UX fixes:
- Quota 0 now displays ∞ (unlimited) in both admin and account views
- Admin mailbox action buttons replaced with Dashicon icon buttons
  (lock, chart-bar, trash) with title tooltips

i18n:
- load_plugin_textdomain registered on init hook
- All user-facing PHP strings wrapped in __() / esc_html__()
- Translated strings array passed to account JS via wp_localize_script
- woocow-es_ES.po/.mo — Spanish translation
- woocow-ro_RO.po/.mo — Romanian translation (with correct plural forms)
- English remains the fallback

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

woocow.php

@@ -25,6 +25,10 @@ require_once WOOCOW_PLUGIN_DIR . 'includes/class-woocow-pw-sync.php';
 
 register_activation_hook( __FILE__, [ 'WooCow_Installer', 'install' ] );
 
+add_action( 'init', function () {
+    load_plugin_textdomain( 'woocow', false, dirname( plugin_basename( WOOCOW_PLUGIN_FILE ) ) . '/languages' );
+} );
+
 add_action( 'plugins_loaded', function () {
     if ( ! class_exists( 'WooCommerce' ) ) {
         add_action( 'admin_notices', function () {