🛠️ Add German portal domain and refactor URL handling for Nostr publishing

- Introduce `portal.einundzwanzig.space` with locale settings in `DomainMiddleware`.
- Replace verbose if‑chain in `NostrTrait::getUrl()` with a concise match expression.
- Add `DOMAIN_MAP` constant to `PublishUnpublishedItems` and force URL generation to use the correct domain per country.
- Update command flow: set domain before configuring timezone/locale.

app/Http/Middleware/DomainMiddleware.php

@@ -15,6 +15,11 @@ class DomainMiddleware
 
         // domains
         $domainArray = [
+            'portal.einundzwanzig.space' => [
+                'locale' => 'de',
+                'lang_country' => 'de-DE',
+                'app_name' => 'EINUNDZWANZIG Portal',
+            ],
             'portal.eenentwintig.net' => [
                 'locale' => 'nl',
                 'lang_country' => 'nl-NL',