refactor(clubSettings): remove myTischtennis club ID and update related logic

- Removed the myTischtennis club ID field from club settings and related backend logic.
- Updated the database migration to eliminate the my_tischtennis_club_id column.
- Adjusted frontend components and services to reflect the removal of the club ID, ensuring the use of association member number instead.
- Enhanced user interface hints to clarify the use of association member number for rankings.

frontend/src/i18n/locales/de.json

@@ -741,10 +741,9 @@
     "myTischtennisRankings": "myTischtennis TTR/QTTR-Ranglisten",
     "myTischtennisRankingsHint": "Automatischer Abruf der Vereins-Rangliste für TTR- und QTTR-Updates der Mitglieder.",
     "autoFetchRankings": "Ranglisten automatisch abrufen",
-    "myTischtennisClubId": "myTischtennis Vereinsnummer",
-    "myTischtennisClubIdPlaceholder": "z. B. 43030",
     "myTischtennisFedNickname": "Verbandskürzel",
-    "myTischtennisFedNicknamePlaceholder": "z. B. HeTTV"
+    "myTischtennisFedNicknamePlaceholder": "z. B. HeTTV",
+    "rankingsUsesAssociationNumber": "Die Vereinsnummer für den Ranglisten-Abruf entspricht der Verbands-Mitgliedsnummer oben."
   },
   "predefinedActivities": {
     "title": "Vordefinierte Aktivitäten",

frontend/src/views/ClubSettings.vue

@@ -61,15 +61,12 @@
         </label>
       </div>
       <div v-if="autoFetchRankings" class="rankings-fields">
-        <div class="field-group">
-          <label>{{ $t('clubSettings.myTischtennisClubId') }}</label>
-          <input v-model="myTischtennisClubId" class="text-input" :placeholder="$t('clubSettings.myTischtennisClubIdPlaceholder')" />
-        </div>
         <div class="field-group">
           <label>{{ $t('clubSettings.myTischtennisFedNickname') }}</label>
           <input v-model="myTischtennisFedNickname" class="text-input" :placeholder="$t('clubSettings.myTischtennisFedNicknamePlaceholder')" />
         </div>
       </div>
+      <p v-if="autoFetchRankings" class="hint">{{ $t('clubSettings.rankingsUsesAssociationNumber') }}</p>
     </section>
 
     <section v-if="currentClub && !loading" class="card actions-card">
@@ -112,7 +109,6 @@ export default {
       activeTab: 'settings',
       greeting: '',
       associationMemberNumber: '',
-      myTischtennisClubId: '',
       myTischtennisFedNickname: '',
       autoFetchRankings: false,
       saved: false,
@@ -136,7 +132,6 @@ export default {
       if (!this.currentClub) {
         this.greeting = '';
         this.associationMemberNumber = '';
-        this.myTischtennisClubId = '';
         this.myTischtennisFedNickname = '';
         this.autoFetchRankings = false;
         this.loadError = null;
@@ -149,14 +144,12 @@ export default {
         const club = response.data;
         this.greeting = club?.greetingText ?? '';
         this.associationMemberNumber = club?.associationMemberNumber ?? '';
-        this.myTischtennisClubId = club?.myTischtennisClubId ?? '';
         this.myTischtennisFedNickname = club?.myTischtennisFedNickname ?? '';
         this.autoFetchRankings = !!club?.autoFetchRankings;
       } catch (e) {
         this.loadError = this.$t('clubSettings.loadFailed');
         this.greeting = '';
         this.associationMemberNumber = '';
-        this.myTischtennisClubId = '';
         this.myTischtennisFedNickname = '';
         this.autoFetchRankings = false;
       } finally {
@@ -172,7 +165,6 @@ export default {
         await apiClient.put(`/clubs/${this.currentClub}/settings`, {
           greetingText: this.greeting,
           associationMemberNumber: this.associationMemberNumber,
-          myTischtennisClubId: this.myTischtennisClubId || null,
           myTischtennisFedNickname: this.myTischtennisFedNickname || null,
           autoFetchRankings: this.autoFetchRankings,
         });
@@ -211,7 +203,7 @@ export default {
 }
 .text-input { width: 100%; border: 1px solid #ddd; border-radius: 6px; padding: 8px; font-size: 14px; }
 .rankings-row { margin-bottom: 12px; }
-.rankings-fields { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 12px; }
+.rankings-fields { margin-top: 12px; }
 .field-group label { display: block; margin-bottom: 4px; font-weight: 500; color: #333; }
 .checkbox-label { display: flex; align-items: center; gap: 8px; cursor: pointer; }
 .checkbox-label input[type="checkbox"] { width: auto; }