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

bootstrap/app.php

@@ -2,6 +2,7 @@
 
 use App\Http\Middleware\HandleAppearance;
 use App\Http\Middleware\HandleInertiaRequests;
+use App\Http\Middleware\SetLocaleFromUser;
 use Illuminate\Foundation\Application;
 use Illuminate\Foundation\Configuration\Exceptions;
 use Illuminate\Foundation\Configuration\Middleware;
@@ -17,6 +18,7 @@ return Application::configure(basePath: dirname(__DIR__))
         $middleware->encryptCookies(except: ['appearance', 'sidebar_state']);
 
         $middleware->web(append: [
+            SetLocaleFromUser::class,
             HandleAppearance::class,
             HandleInertiaRequests::class,
             AddLinkHeadersForPreloadedAssets::class,