feat(admin): implement delete functionality for Falukant regions and update UI components

backend/services/adminService.js

@@ -934,6 +934,45 @@ class AdminService {
         return region;
     }
 
+    async deleteFalukantRegion(userId, regionId) {
+        if (!(await this.hasUserAccess(userId, 'falukantusers'))) {
+            throw new Error('noaccess');
+        }
+
+        const region = await RegionData.findByPk(regionId);
+        if (!region) {
+            throw new Error('regionNotFound');
+        }
+
+        const [childCount, distanceCount, userCount, characterCount, weatherCount] = await Promise.all([
+            RegionData.count({ where: { parentId: region.id } }),
+            RegionDistance.count({
+                where: {
+                    [Op.or]: [
+                        { sourceRegionId: region.id },
+                        { targetRegionId: region.id },
+                    ],
+                },
+            }),
+            FalukantUser.count({ where: { mainBranchRegionId: region.id } }),
+            FalukantCharacter.count({ where: { regionId: region.id } }),
+            Weather.count({ where: { regionId: region.id } }),
+        ]);
+
+        if (childCount > 0) {
+            throw new Error('regionHasChildren');
+        }
+        if (distanceCount > 0) {
+            throw new Error('regionHasDistances');
+        }
+        if (userCount > 0 || characterCount > 0 || weatherCount > 0) {
+            throw new Error('regionInUse');
+        }
+
+        await region.destroy();
+        return { success: true };
+    }
+
     async getRegionDistances(userId) {
         if (!(await this.hasUserAccess(userId, 'falukantusers'))) {
             throw new Error('noaccess');