Enhance permission validation and error handling in permissionController

Updated the getUserPermissions function to include validation for clubId, ensuring it is a valid positive integer. Added error handling to return a 400 status with a descriptive message for invalid club IDs, improving the robustness of the API response.

backend/controllers/permissionController.js

@@ -8,7 +8,13 @@ export const getUserPermissions = async (req, res) => {
     const { clubId } = req.params;
     const userId = req.user.id;
 
-    const permissions = await permissionService.getUserClubPermissions(userId, parseInt(clubId));
+    // Validierung: clubId muss eine gültige Zahl sein
+    const parsedClubId = parseInt(clubId, 10);
+    if (isNaN(parsedClubId) || parsedClubId <= 0) {
+      return res.status(400).json({ error: 'Ungültige Club-ID' });
+    }
+
+    const permissions = await permissionService.getUserClubPermissions(userId, parsedClubId);
 
     if (!permissions) {
       return res.status(404).json({ error: 'Keine Berechtigungen gefunden' });