feat: filter teams with zero members in admin components

- Updated `AdminClientWrapper` to filter out teams with zero members in `getFilteredTeamStats`.
- Modified `AdminFilters` to only include directions and teams with members in the options.
- Enhanced `AdminService` to generate direction stats based on teams with members, improving data accuracy.

components/admin/admin-client-wrapper.tsx

@@ -35,6 +35,9 @@ export function AdminClientWrapper({
   const getFilteredTeamStats = () => {
     let filtered = teamStats;
 
+    // Filtrer les équipes avec 0 membres
+    filtered = filtered.filter((team) => team.totalMembers > 0);
+
     if (selectedDirections.length > 0) {
       filtered = filtered.filter((team) =>
         selectedDirections.includes(team.direction)