feat(tournament): add cleanup logic for orphaned matches

- Implemented a new method to clean up orphaned matches where at least one player no longer exists, enhancing data integrity in tournament management.
- Added a corresponding route and frontend functionality to trigger the cleanup process, allowing users to easily remove invalid match records.
- Updated localization strings to support the new feature, ensuring clarity in the user interface.

frontend/src/components/tournament/TournamentGroupsTab.vue

@@ -162,8 +162,14 @@
                 <button @click="$emit('create-matches')" class="btn-primary">
                     ▶️ Gruppenspiele berechnen
                 </button>
+                <button @click="$emit('cleanup-orphaned-matches')" class="btn-secondary">
+                    🧹 {{ $t('tournaments.cleanupOrphanedMatches') }}
+                </button>
             </div>
             <div v-if="filteredGroupMatches.length > 0" class="reset-controls" style="margin-top:1rem">
+                <button @click="$emit('cleanup-orphaned-matches')" class="btn-secondary">
+                    🧹 {{ $t('tournaments.cleanupOrphanedMatches') }}
+                </button>
                 <button @click="$emit('reset-matches')" class="trash-btn">
                     🗑️ {{ $t('tournaments.resetGroupMatches') }}
                 </button>
@@ -246,6 +252,7 @@ export default {
         'randomize-groups',
         'reset-groups',
         'reset-matches',
+        'cleanup-orphaned-matches',
         'create-matches',
         'highlight-match',
         'go-to-match',

frontend/src/i18n/locales/de.json

@@ -648,6 +648,7 @@
     "errorMoreSeededThanUnseeded": "Es gibt mehr gesetzte als nicht gesetzte Spieler. Zufällige Paarungen können nicht erstellt werden.",
     "randomPairingsCreated": "Zufällige Paarungen wurden erstellt.",
     "resetGroupMatches": "Gruppenspiele",
+    "cleanupOrphanedMatches": "Verwaiste Spiele aufräumen",
     "groupMatches": "Gruppenspiele",
     "round": "Runde",
     "encounter": "Begegnung",

frontend/src/views/TournamentTab.vue

@@ -198,6 +198,7 @@
                 @randomize-groups="randomizeGroups()"
                 @reset-groups="resetGroups()"
                 @reset-matches="resetMatches()"
+                @cleanup-orphaned-matches="cleanupOrphanedMatches()"
                 @create-matches="createMatches()"
                 @highlight-match="highlightMatch"
                 @go-to-match="goToMatch"
@@ -2084,6 +2085,26 @@ export default {
             await this.loadTournamentData();
         },
 
+        async cleanupOrphanedMatches() {
+            try {
+                const res = await apiClient.post('/tournament/matches/cleanup-orphaned', {
+                    clubId: this.currentClub,
+                    tournamentId: this.selectedDate
+                });
+                const count = res.data?.deletedCount ?? 0;
+                await this.loadTournamentData();
+                if (count > 0) {
+                    await this.showInfo(this.$t('messages.success'), `${count} ${count === 1 ? 'Spiel' : 'Spiele'} entfernt.`, '');
+                } else {
+                    await this.showInfo(this.$t('messages.info'), 'Keine verwaisten Spiele gefunden.', '');
+                }
+            } catch (error) {
+                console.error('Fehler beim Aufräumen:', error);
+                const message = safeErrorMessage(error, 'Fehler beim Aufräumen verwaister Spiele.');
+                await this.showInfo(this.$t('messages.error'), message, '', 'error');
+            }
+        },
+
         async removeParticipant(p) {
             try {
                 if (this.allowsExternal && p.isExternal) {