Add optional chaining for response.data.roles access in getUserDetail

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/stores/acctMgmt.ts

@@ -267,7 +267,7 @@ export const useAcctMgmtStore = defineStore('acctMgmtStore', {
       try {
         const response = await apiClient.get(apiUserDetail);
         this.currentViewingUser = response.data;
-        this.currentViewingUser.is_admin = response.data.roles.some(role => role.code === 'admin');
+        this.currentViewingUser.is_admin = response.data.roles?.some(role => role.code === 'admin') ?? false;
         return response.status === 200;
       } catch (error) {
         // No need to show an error, because an error here means the account is unique