Stand: SMTP-Test, Admin-Mail-Tab, Notifiable-Fix, Lazy-Quill

- Fix: Notifiable-Trait zum User-Model hinzugefuegt (behebt notify()-500er)
- Installer: SMTP-Verbindungstest mit EsmtpTransport + Ueberspringen-Link
- Admin: Neuer E-Mail-Tab mit SMTP-Konfiguration + Verbindungstest
- Admin: Lazy Quill-Initialisierung (nur sichtbare Locale wird geladen)
- Uebersetzungen: 17 neue Mail-Keys in allen 6 Sprachen

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

vendor/symfony/polyfill-intl-idn/Resources/unidata/disallowed_STD3_valid.php

@@ -0,0 +1,71 @@
+<?php
+
+return array (
+  0 => true,
+  1 => true,
+  2 => true,
+  3 => true,
+  4 => true,
+  5 => true,
+  6 => true,
+  7 => true,
+  8 => true,
+  9 => true,
+  10 => true,
+  11 => true,
+  12 => true,
+  13 => true,
+  14 => true,
+  15 => true,
+  16 => true,
+  17 => true,
+  18 => true,
+  19 => true,
+  20 => true,
+  21 => true,
+  22 => true,
+  23 => true,
+  24 => true,
+  25 => true,
+  26 => true,
+  27 => true,
+  28 => true,
+  29 => true,
+  30 => true,
+  31 => true,
+  32 => true,
+  33 => true,
+  34 => true,
+  35 => true,
+  36 => true,
+  37 => true,
+  38 => true,
+  39 => true,
+  40 => true,
+  41 => true,
+  42 => true,
+  43 => true,
+  44 => true,
+  47 => true,
+  58 => true,
+  59 => true,
+  60 => true,
+  61 => true,
+  62 => true,
+  63 => true,
+  64 => true,
+  91 => true,
+  92 => true,
+  93 => true,
+  94 => true,
+  95 => true,
+  96 => true,
+  123 => true,
+  124 => true,
+  125 => true,
+  126 => true,
+  127 => true,
+  8800 => true,
+  8814 => true,
+  8815 => true,
+);