fix(07): UAT fixes — SMTP test email, DKV routing, Exchange domain field

- SMTP: add test-to field, send real email via sendMail() instead of verify()
- SMTP: fix no_auth warning shown as error for open-relay servers
- DKV: register dkv-fleet in MODULE_REGISTRY (fixes "Modul nicht gefunden")
- DKV: add dynamic [category]/[moduleSlug]/settings + vehicles sub-routes
- DKV: settings/vehicles links use useParams for consistent URLs
- DKV: add gear icon settings link to module main page
- DKV: rename module to "DKV-Rechnung" in seed + translations
- DKV: add optional domain field for Exchange (WebCredentials 3rd arg)
- DKV: hide IMAP-only fields (Port/Verschlüsselung/Ordner) when Exchange selected
- DKV: hide Exchange-only field (Domain) when IMAP selected
- Prisma: add domain column to DkvModuleConfig

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

apps/web/src/components/settings/smtp-settings-form.tsx

@@ -51,6 +51,7 @@ export function SmtpSettingsForm() {
   const t = useTranslations('settings');
 
   const [form, setForm] = useState<FormState>(DEFAULT_FORM);
+  const [testTo, setTestTo] = useState('');
   const [isSaving, setIsSaving] = useState(false);
   const [isTesting, setIsTesting] = useState(false);
   const [showPassword, setShowPassword] = useState(false);
@@ -114,10 +115,10 @@ export function SmtpSettingsForm() {
     setIsTesting(true);
     setTestFeedback({ type: 'loading', message: t('smtp.testTesting') });
     try {
-      const result = await testSmtp(buildPayload());
-      if (result.success && result.warning === 'no_auth') {
-        setTestFeedback({ type: 'error', message: t('smtp.testNoAuth') });
-      } else if (result.success) {
+      const payload = buildPayload();
+      if (testTo.trim()) payload.testTo = testTo.trim();
+      const result = await testSmtp(payload);
+      if (result.success) {
         setTestFeedback({ type: 'success', message: t('smtp.testSuccess') });
       } else {
         setTestFeedback({ type: 'error', message: t('smtp.testFailed') });
@@ -126,7 +127,6 @@ export function SmtpSettingsForm() {
       setTestFeedback({ type: 'error', message: t('smtp.testFailed') });
     } finally {
       setIsTesting(false);
-      // Auto-clear after 6 seconds
       clearTimerRef.current = setTimeout(() => setTestFeedback(null), 6000);
     }
   };
@@ -300,6 +300,24 @@ export function SmtpSettingsForm() {
         </p>
       </div>
 
+      {/* Test-E-Mail Empfänger */}
+      <div>
+        <label htmlFor="smtp-test-to" className={labelClass}>
+          {t('smtp.testToLabel')}
+        </label>
+        <input
+          id="smtp-test-to"
+          type="email"
+          placeholder={t('smtp.testToPlaceholder')}
+          className={inputClass}
+          value={testTo}
+          onChange={(e) => setTestTo(e.target.value)}
+        />
+        <p className="mt-1 text-xs text-muted-foreground">
+          {t('smtp.testToHelp')}
+        </p>
+      </div>
+
       {/* Action row */}
       <div className="flex gap-3 pt-2">
         <button