feat(clubSettings): enhance club settings UI with loading and error handling

- Added loading and error states to the club settings view, improving user feedback during data retrieval.
- Introduced new translations for error messages in the German locale, enhancing localization support.
- Updated the save method to alert users when no club is selected, ensuring clarity in user actions.

frontend/src/i18n/locales/de.json

@@ -735,7 +735,9 @@
     "associationMemberNumberPlaceholder": "z. B. 12-3456",
     "save": "Speichern",
     "saved": "Gespeichert",
-    "saveFailed": "Speichern fehlgeschlagen"
+    "saveFailed": "Speichern fehlgeschlagen",
+    "loadFailed": "Einstellungen konnten nicht geladen werden",
+    "noClubSelected": "Bitte wählen Sie zuerst einen Verein aus."
   },
   "predefinedActivities": {
     "title": "Vordefinierte Aktivitäten",

frontend/src/views/ClubSettings.vue

@@ -26,7 +26,10 @@
 
     <!-- Settings Tab -->
     <div v-if="activeTab === 'settings'">
-    <section class="card">
+    <p v-if="!currentClub" class="hint hint-warning">{{ $t('clubSettings.noClubSelected') }}</p>
+    <p v-else-if="loading" class="hint">{{ $t('common.loading') }}</p>
+    <p v-else-if="loadError" class="hint hint-error">{{ loadError }}</p>
+    <section v-if="currentClub && !loading" class="card">
       <h2>{{ $t('clubSettings.greetingText') }}</h2>
       <div class="greeting-grid">
         <textarea v-model="greeting" class="greeting-input" rows="10" :placeholder="$t('clubSettings.greetingPlaceholder')"></textarea>
@@ -43,12 +46,12 @@
       <p class="hint">{{ $t('clubSettings.greetingHint') }}</p>
     </section>
 
-    <section class="card">
+    <section v-if="currentClub && !loading" class="card">
       <h2>{{ $t('clubSettings.associationMemberNumber') }}</h2>
       <input v-model="associationMemberNumber" class="text-input" :placeholder="$t('clubSettings.associationMemberNumberPlaceholder')" />
     </section>
 
-    <section class="card actions-card">
+    <section v-if="currentClub && !loading" class="card actions-card">
       <div class="actions">
         <button class="btn btn-primary" @click="save">{{ $t('clubSettings.save') }}</button>
         <span v-if="saved" class="saved-hint">{{ $t('clubSettings.saved') }}</span>
@@ -72,6 +75,7 @@
   </template>
 
 <script>
+import { mapGetters } from 'vuex';
 import apiClient from '../apiClient';
 import TrainingGroupsTab from '../components/TrainingGroupsTab.vue';
 import TrainingTimesTab from '../components/TrainingTimesTab.vue';
@@ -88,27 +92,54 @@ export default {
       greeting: '',
       associationMemberNumber: '',
       saved: false,
+      loading: false,
+      loadError: null,
     };
   },
-  mounted() {
-    const stored = localStorage.getItem('clubGreeting');
-    if (stored) this.greeting = stored;
-    const storedNr = localStorage.getItem('associationMemberNumber');
-    if (storedNr) this.associationMemberNumber = storedNr;
+  computed: {
+    ...mapGetters(['currentClub']),
+  },
+  watch: {
+    currentClub: {
+      handler(clubId) {
+        if (clubId) this.loadClubSettings();
+      },
+      immediate: true,
+    },
   },
   methods: {
-    async save() {
-      localStorage.setItem('clubGreeting', this.greeting || '');
-      localStorage.setItem('associationMemberNumber', this.associationMemberNumber || '');
+    async loadClubSettings() {
+      if (!this.currentClub) {
+        this.greeting = '';
+        this.associationMemberNumber = '';
+        this.loadError = null;
+        return;
+      }
+      this.loadError = null;
+      this.loading = true;
       try {
-        // Beispiel: aktuellen Club aus localStorage
-        const clubId = localStorage.getItem('currentClub');
-        if (clubId) {
-          await apiClient.put(`/clubs/${clubId}/settings`, {
-            greetingText: this.greeting,
-            associationMemberNumber: this.associationMemberNumber,
-          });
-        }
+        const response = await apiClient.get(`/clubs/${this.currentClub}`);
+        const club = response.data;
+        this.greeting = club?.greetingText ?? '';
+        this.associationMemberNumber = club?.associationMemberNumber ?? '';
+      } catch (e) {
+        this.loadError = this.$t('clubSettings.loadFailed');
+        this.greeting = '';
+        this.associationMemberNumber = '';
+      } finally {
+        this.loading = false;
+      }
+    },
+    async save() {
+      if (!this.currentClub) {
+        alert(this.$t('clubSettings.noClubSelected'));
+        return;
+      }
+      try {
+        await apiClient.put(`/clubs/${this.currentClub}/settings`, {
+          greetingText: this.greeting,
+          associationMemberNumber: this.associationMemberNumber,
+        });
         this.saved = true;
         setTimeout(() => (this.saved = false), 1500);
       } catch (e) {
@@ -148,6 +179,8 @@ export default {
 .btn.btn-primary:hover { background: var(--primary-hover); }
 .saved-hint { color: #28a745; font-weight: 600; }
 .hint { color: #666; font-size: 12px; margin-top: 8px; }
+.hint-warning { color: #856404; background: #fff3cd; padding: 12px; border-radius: 6px; }
+.hint-error { color: #721c24; background: #f8d7da; padding: 12px; border-radius: 6px; }
 
 .tab-navigation {
     display: flex;