feat(tournament): refine mini championship creation and UI integration

- Updated the addMiniChampionship method to default winning sets to 1 and added transaction handling for improved reliability.
- Enhanced frontend components to include a new property for mini championship identification, ensuring proper configuration in the UI.
- Adjusted the display logic in TournamentConfigTab to conditionally render stage configuration based on the mini championship type.

frontend/src/components/tournament/TournamentConfigTab.vue

@@ -48,7 +48,7 @@
             @update:newClassMinBirthYear="$emit('update:newClassMinBirthYear', $event)"
         />
 
-        <div class="stage-config" style="margin-top: 1.5rem;">
+        <div v-if="!isMiniChampionship" class="stage-config" style="margin-top: 1.5rem;">
             <h3>Zwischenrunde & Endrunde</h3>
             <div v-if="stageConfig.loading" style="opacity: 0.8;">
                 Lade Zwischenrunden …
@@ -224,6 +224,10 @@ export default {
             type: Boolean,
             required: true
         },
+        isMiniChampionship: {
+            type: Boolean,
+            default: false
+        },
         tournamentClasses: {
             type: Array,
             required: true

frontend/src/views/TournamentTab.vue

@@ -95,6 +95,7 @@
                 :club-id="currentClub"
                 :tournament-id="selectedDate"
                 :tournament-name="currentTournamentName"
+                :is-mini-championship="isMiniChampionship"
                 :tournament-date="currentTournamentDate"
                 :winning-sets="currentWinningSets"
                 :is-group-tournament="isGroupTournament"