feat(PROJ-28): FQDN + smtp_out Konfiguration

- config: server.fqdn, SMTPOutConfig, smtp_out Abschnitt
- config: IMAPServerConfig.FQDN (runtime-gesetzt)
- main: FQDN-Fallback für SMTP EHLO, FQDN an IMAP-Server
- imapserver: Greeting nutzt server.fqdn (RFC 3501)
- smtpd/imapserver Modulversion 1.3

fix: Superadmin sieht keine Suche/IMAP/POP3 Nav-Links

- Navbar: Suche, IMAP Import, POP3 Import nur für non-superadmin
- Superadmin landet direkt auf Admin-Dashboard

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

src/components/navbar.tsx

@@ -23,24 +23,30 @@ export function Navbar({ username, role }: NavbarProps) {
           >
             archivmail
           </Link>
-          <Link
-            href="/search"
-            className="text-sm text-muted-foreground hover:text-foreground transition-colors"
-          >
-            Suche
-          </Link>
-          <Link
-            href="/imap"
-            className="text-sm text-muted-foreground hover:text-foreground transition-colors"
-          >
-            IMAP Import
-          </Link>
-          <Link
-            href="/pop3"
-            className="text-sm text-muted-foreground hover:text-foreground transition-colors"
-          >
-            POP3 Import
-          </Link>
+          {role !== "superadmin" && (
+            <Link
+              href="/search"
+              className="text-sm text-muted-foreground hover:text-foreground transition-colors"
+            >
+              Suche
+            </Link>
+          )}
+          {role !== "superadmin" && (
+            <Link
+              href="/imap"
+              className="text-sm text-muted-foreground hover:text-foreground transition-colors"
+            >
+              IMAP Import
+            </Link>
+          )}
+          {role !== "superadmin" && (
+            <Link
+              href="/pop3"
+              className="text-sm text-muted-foreground hover:text-foreground transition-colors"
+            >
+              POP3 Import
+            </Link>
+          )}
           {(role === "admin" || role === "domain_admin" || role === "superadmin") && (
             <Link
               href="/admin"