fix(backend): Verschillende kleine fixes

frontend/src/components/UsingQueryResult.vue

@@ -12,7 +12,7 @@
     const { t } = useI18n();
 
     const errorMessage = computed(() => {
-        let errorWithMessage = (error as {message: string}) || null;
+        let errorWithMessage = (error.value as {message: string}) || null;
         return errorWithMessage?.message || JSON.stringify(errorWithMessage)
     });
 </script>

frontend/src/views/learning-paths/LearningObjectView.vue

@@ -29,4 +29,10 @@ const learningObjectHtmlQueryResult: UseQueryReturnType<Document, Error> = useLe
         margin-top: 5px;
         margin-bottom: 5px;
     }
+    :deep(img) {
+        max-width: 80%;
+    }
+    :deep(h2), :deep(h3), :deep(h4), :deep(h5), :deep(h6) {
+        margin-top: 10px;
+    }
 </style>

frontend/src/views/learning-paths/LearningPathPage.vue

@@ -145,12 +145,13 @@
                     :query-result="learningObjectListQueryResult"
                     v-slot="learningObjects: {data: LearningObject[]}"
                 >
+                    <template v-for="node in learningObjects.data">
                         <v-list-item
                             link
                             :to="{path: node.key, query: route.query}"
                             :title="node.title"
                             :active="node.key === props.learningObjectHruid"
-                        v-for="node in learningObjects.data"
+                            v-if="!node.teacherExclusive || authService.authState.activeRole === 'teacher'"
                         >
                             <template v-slot:prepend>
                                 <v-icon
@@ -161,6 +162,7 @@
                                 {{ node.estimatedTime }}'
                             </template>
                         </v-list-item>
+                    </template>
                 </using-query-result>
             </div>
         </v-navigation-drawer>