Add default question block structure and validation for properties in question editor

atlas/templates/atlas/collection_case_questions.html

@@ -268,6 +268,14 @@
                     currentContent = JSON.parse(JSON.stringify(question_editor.get().json));
                 }
 
+                if (!currentContent) {
+                    currentContent = {
+                        title: questionBlockTitleInput.value || "Case Questions",
+                        type: "object",
+                        properties: {}
+                    };
+                }
+
                 if (!currentContent.properties) {
                     currentContent.properties = {};
                     current_question_number = 1;
@@ -402,6 +410,10 @@
                         } catch {
                             currentContent = JSON.parse(JSON.stringify(question_editor.get().json));
                         }
+                        if (!currentContent || !currentContent.properties) {
+                            console.warn('No properties found in the current content.');
+                            return;
+                        }
                         const properties = currentContent.properties || {};
 
                         // Sort questions by propertyOrder