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>

cmd/archivmail/main.go

@@ -209,6 +209,7 @@ func main() {
 
 	// PROJ-26: IMAP Archive Server (read-only access for IMAP clients)
 	if cfg.IMAPServer.Enabled {
+		cfg.IMAPServer.FQDN = cfg.Server.FQDN
 		imapSrv := imapserver.New(cfg.IMAPServer, mailStore, users, labelSt, audlog, authMgr, logger, tenantSt)
 		if err := imapSrv.Start(); err != nil {
 			logger.Error("IMAP server failed to start", "err", err)
@@ -226,6 +227,10 @@ func main() {
 	if cfg.SMTP.Bind == "" {
 		cfg.SMTP.Bind = fmt.Sprintf(":%d", cfg.Server.SMTPPort)
 	}
+	// PROJ-28: FQDN fallback for SMTP EHLO banner
+	if cfg.SMTP.Domain == "" && cfg.Server.FQDN != "" {
+		cfg.SMTP.Domain = cfg.Server.FQDN
+	}
 	smtpDaemon := smtpd.New(cfg.SMTP, mailStore, logger)
 	smtpDaemon.SetIndexCallback(func(raw []byte, id string) {
 		// Look up the tenant_id for this email from DB metadata.

cmd/archivmail/version.go

@@ -13,8 +13,8 @@ const AppVersion = "0.9.1"
 // MINOR: Neue Funktionen, Bugfixes, Security-Patches
 var Modules = map[string]string{
 	"storage":     "1.7", // PROJ-33 MailWithUID, GetMailsWithUID, GetMailsByRecipient
-	"smtpd":       "1.2", // IP-Allowlist fail-closed, Domain→Tenant-Routing
-	"imapserver":  "1.2", // PROJ-33 UID-Stabilität, shared/personal IMAP-Modus
+	"smtpd":       "1.3", // PROJ-28 FQDN-Fallback für EHLO-Banner
+	"imapserver":  "1.3", // PROJ-28 FQDN-Greeting (RFC 3501)
 	"auth":        "1.3", // JWT, bcrypt cost 12, TOTP
 	"audit":       "1.1", // PostgreSQL append-only, QueryFilter
 	"index":       "1.0", // Xapian-Wrapper, Async-Worker, Tenant-Index