feat(profile): add username + preferred_locale; wire to Inertia + middleware

- DB: users.username (unique), users.preferred_locale (default from app.locale)
- Backend: validation, model fillable; share supportedLocales; SetLocaleFromUser
- Frontend: profile page fields + types
- Filament: SuperAdmin profile page with username/language

feat(admin-nav): move Tasks to Bibliothek and add menu labels

fix(tasks-table): show localized title/emotion/event type; add translated headers

feat(l10n): add missing table headers for emotions and event types; normalize en/de files

refactor: tidy translations for tasks/emotions/event types

resources/views/filament/events/join-link.blade.php

@@ -1,15 +1,16 @@
 <div class="space-y-3">
-  <div class="text-sm">Join Link</div>
+  <div class="text-sm">{{ __('admin.events.join_link.link_label') }}</div>
   <div class="rounded border bg-gray-50 p-2 text-sm dark:bg-gray-900">
     <a href="{{ $link }}" target="_blank" class="underline">
       {{ $link }}
     </a>
   </div>
-  <div class="text-sm">QR Code</div>
+  <div class="text-sm">{{ __('admin.events.join_link.qr_code_label') }}</div>
   <div class="flex items-center justify-center">
     {!! \SimpleSoftwareIO\QrCode\Facades\QrCode::size(300)->generate($link) !!}
   </div>
   <div class="text-xs text-muted-foreground">
-    Hinweis: Der QR-Code wird über einen externen QR-Service generiert. Für eine selbst gehostete Lösung können wir später eine interne QR-Generierung ergänzen.
+    {!! __('admin.events.join_link.note_html') !!}
   </div>
 </div>
+