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

app/Providers/Filament/SuperAdminPanelProvider.php

@@ -27,6 +27,7 @@ class SuperAdminPanelProvider extends PanelProvider
             ->default()
             ->id('super-admin')
             ->path('super-admin')
+            ->profile(\App\Filament\Pages\SuperAdminProfile::class, true)
             ->colors([
                 'primary' => Color::Amber,
             ])