Refactor character creation and heir fetching logic in FalukantService and OverviewView

- Updated character creation process to utilize transactions for improved data integrity during heir generation.
- Enhanced heir fetching logic in OverviewView to check for both mainBranchRegion.id and mainBranchRegionId, adding error handling for missing regions.
- Added warnings for empty heir responses from the API to improve debugging and user feedback.

frontend/src/views/falukant/OverviewView.vue

@@ -339,13 +339,23 @@ export default {
             return new Date(timestamp).toLocaleString();
         },
         async fetchPotentialHeirs() {
-            if (!this.falukantUser?.mainBranchRegion?.id) return;
+            // Prüfe sowohl mainBranchRegion.id als auch mainBranchRegionId
+            const regionId = this.falukantUser?.mainBranchRegion?.id || this.falukantUser?.mainBranchRegionId;
+            if (!regionId) {
+                console.error('No main branch region found', this.falukantUser);
+                this.potentialHeirs = [];
+                return;
+            }
             this.loadingHeirs = true;
             try {
                 const response = await apiClient.get('/api/falukant/heirs/potential');
                 this.potentialHeirs = response.data || [];
+                if (this.potentialHeirs.length === 0) {
+                    console.warn('No potential heirs returned from API');
+                }
             } catch (error) {
                 console.error('Error fetching potential heirs:', error);
+                console.error('Error details:', error.response?.data || error.message);
                 this.potentialHeirs = [];
             } finally {
                 this.loadingHeirs = false;