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/lib/dkv-api.ts

@@ -28,6 +28,7 @@ export interface DkvConfig {
   exportRecipient: string;
   vehicleFormatString: string;
   username?: string | null;
+  domain?: string | null;
   /** true if a password is stored server-side — never the actual secret */
   hasPassword: boolean;
 }

apps/web/src/lib/module-loader.ts

@@ -35,6 +35,12 @@ export const MODULE_REGISTRY: Record<string, ModuleRegistryEntry> = {
       { ssr: false },
     ),
   },
+  'dkv-fleet': {
+    component: dynamic(
+      () => import('@/app/(portal)/modules/dkv-fleet/page'),
+      { ssr: false },
+    ),
+  },
 };
 
 /**

apps/web/src/lib/settings-api.ts

@@ -37,6 +37,8 @@ export interface SaveSmtpPayload {
   /** Only include when the user has typed a new password. */
   password?: string;
   fromAddress: string;
+  /** If set, backend sends a real test email to this address instead of just verify(). */
+  testTo?: string;
 }
 
 // --- API functions ---