Refactor localization handling in frontend components to use centralized i18n instance

This commit updates the localization implementation in App.vue, LogsView.vue, and PermissionsView.vue by replacing the use of `useI18n` with a direct import of the i18n instance. This change simplifies the translation function calls and ensures consistency across the application.

frontend/src/App.vue

@@ -336,7 +336,7 @@ export default {
     
     // Synchronisiere Sprache aus Store mit i18n
     if (this.language) {
-      this.$i18n.locale.value = this.language;
+      this.$i18n.locale = this.language;
     }
     
     // Nur Daten laden, wenn der Benutzer authentifiziert ist

frontend/src/views/LogsView.vue

@@ -193,7 +193,7 @@
 
 <script>
 import { ref, computed, onMounted } from 'vue';
-import { useI18n } from 'vue-i18n';
+import i18n from '../i18n';
 import apiClient from '../apiClient.js';
 import InfoDialog from '../components/InfoDialog.vue';
 
@@ -203,7 +203,7 @@ export default {
     InfoDialog
   },
   setup() {
-    const { t } = useI18n();
+    const t = (key, params) => i18n.global.t(key, params);
     const logs = ref([]);
     const total = ref(0);
     const loading = ref(false);

frontend/src/views/PermissionsView.vue

@@ -155,7 +155,7 @@
 <script>
 import { ref, computed, onMounted } from 'vue';
 import { useStore } from 'vuex';
-import { useI18n } from 'vue-i18n';
+import i18n from '../i18n';
 import apiClient from '../apiClient.js';
 import { usePermissions } from '../composables/usePermissions.js';
 import InfoDialog from '../components/InfoDialog.vue';
@@ -169,7 +169,7 @@ export default {
   },
   setup() {
     const store = useStore();
-    const { t } = useI18n();
+    const t = (key, params) => i18n.global.t(key, params);
     const { isOwner, isAdmin, can } = usePermissions();
     
     const infoDialog = ref({