feat(nav): single Calendar menu — hide Appointments resource from sidebar

AppointmentResource::\$shouldRegisterNavigation = false so only
CalendarBoard shows in the sidebar as "Calendar". The board already
has a "Listă" view-mode button alongside Zi/Săpt/Lună/Custom, so both
use cases are covered from a single entry. CRUD routes
(/app/appointments/create, /{id}/edit) stay accessible from the
board's click handlers.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/Filament/Tenant/Resources/AppointmentResource.php

@@ -22,6 +22,12 @@ class AppointmentResource extends Resource
 
     protected static string|\BackedEnum|null $navigationIcon = 'heroicon-o-calendar-days';
 
+    /**
+     * Hidden from sidebar — CalendarBoard is the single Calendar entry.
+     * Create/edit routes remain reachable from board click handlers.
+     */
+    protected static bool $shouldRegisterNavigation = false;
+
     public static function getNavigationLabel(): string
     {
         return __('nav.label.Calendar');