feat(match): normalize player lists before updating match data

- Added a `normalizeList` function to filter out duplicates and invalid entries from player arrays.
- Updated the match update logic to use normalized player lists for `playersReady`, `playersPlanned`, and `playersPlayed`.
- Enhanced error handling in the ScheduleView to throw an error for failed match updates based on response status.

backend/services/matchService.js

@@ -443,11 +443,29 @@ class MatchService {
         
         await checkAccess(userToken, match.clubId);
         
-        // Update player arrays
+        const normalizeList = (list) => {
+            if (!Array.isArray(list)) return null;
+            const seen = new Set();
+            const result = [];
+            for (const value of list) {
+                if (value === null || value === undefined) continue;
+                const key = String(value);
+                if (seen.has(key)) continue;
+                seen.add(key);
+                result.push(value);
+            }
+            return result;
+        };
+
+        const readyList = normalizeList(playersReady);
+        const plannedList = normalizeList(playersPlanned);
+        const playedList = normalizeList(playersPlayed);
+
+        // Wenn Listen übergeben wurden, gelten sie als Quelle der Wahrheit
         await match.update({
-            playersReady: playersReady || [],
-            playersPlanned: playersPlanned || [],
-            playersPlayed: playersPlayed || []
+            playersReady: readyList !== null ? readyList : (match.playersReady || []),
+            playersPlanned: plannedList !== null ? plannedList : (match.playersPlanned || []),
+            playersPlayed: playedList !== null ? playedList : (match.playersPlayed || [])
         });
         
         return {