feat: update navigation link for club payments in dashboard and enhance error handling in Home view

frontend/src/views/Home.vue

@@ -105,7 +105,12 @@
           </article>
         </div>
       </section>
-      <section v-if="!dashboardLoading && clubDashboardSections.length === 0" class="card club-dashboard-empty">
+      <section v-if="dashboardError" class="card club-dashboard-empty state-banner state-banner-error">
+        <h3>Dashboard konnte nicht geladen werden</h3>
+        <p>{{ dashboardError }}</p>
+        <button type="button" class="btn-secondary" @click="loadClubDashboard">Erneut versuchen</button>
+      </section>
+      <section v-else-if="!dashboardLoading && clubDashboardSections.length === 0" class="card club-dashboard-empty">
         <h3>Noch keine Dashboard-Daten</h3>
         <p v-if="!currentClub">
           Wähle zuerst einen Verein aus, damit Aufgaben, Mitglieder, Trainings und Termine geladen werden.
@@ -743,6 +748,7 @@ export default {
     return {
       dashboardSectionsOverride: null,
       dashboardLoading: false,
+      dashboardError: '',
     };
   },
   computed: {
@@ -793,22 +799,28 @@ export default {
         await this.loadClubDashboard();
       },
     },
+    appProduct() {
+      this.loadClubDashboard();
+    },
   },
   methods: {
     ...mapActions(['logout']),
     async loadClubDashboard() {
       if (!this.isTtVereinProduct || !this.isAuthenticated || !this.currentClub) {
         this.dashboardSectionsOverride = null;
+        this.dashboardError = '';
         return;
       }
 
       this.dashboardLoading = true;
+      this.dashboardError = '';
       try {
         const response = await apiClient.get(`/club-dashboard/${this.currentClub}`);
         const sections = Array.isArray(response.data?.sections) ? response.data.sections : null;
         this.dashboardSectionsOverride = sections && sections.length > 0 ? sections : null;
-      } catch (_error) {
+      } catch (error) {
         this.dashboardSectionsOverride = null;
+        this.dashboardError = error?.response?.data?.error || 'Bitte prüfe deine Verbindung und versuche es erneut.';
       } finally {
         this.dashboardLoading = false;
       }