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/Pages/CalendarBoard.php

@@ -17,7 +17,7 @@ class CalendarBoard extends Page
 
     public static function getNavigationLabel(): string
     {
-        return __('nav.label.Calendar vizual');
+        return __('nav.label.Calendar');
     }
 
     public static function getNavigationGroup(): ?string
@@ -25,16 +25,7 @@ class CalendarBoard extends Page
         return __('nav.group.CRM');
     }
 
-    /**
-     * Nest this page under the "Calendar" (Programări) list resource so the
-     * two show up as a single expandable menu item in the sidebar.
-     */
-    public static function getNavigationParentItem(): ?string
-    {
-        return __('nav.label.Calendar');
-    }
-
-    protected static ?int $navigationSort = 8;
+    protected static ?int $navigationSort = 7;
 
     protected static ?string $title = null;