fix: Add username uniqueness check to admin user seeding

server/db/create-admin-user.js

@@ -97,12 +97,20 @@ const input = async (fieldName, options = {}) => {
           USERNAME_REGEX.test(process.env.DEFAULT_ADMIN_USERNAME);
 
         if (isValid) {
+          const existingUser = await knex('user_account')
+            .where('username', process.env.DEFAULT_ADMIN_USERNAME.toLowerCase())
+            .first();
+
+          if (!existingUser) {
             break;
           }
 
+          console.log('Username is already in use.');
+        } else {
           console.log(
             'Username must be 3-32 characters and contain only letters, digits, underscores, and dots (e.g., john_doe).',
           );
+        }
 
         process.env.DEFAULT_ADMIN_USERNAME = await input('Username');
 

server/db/seeds/default.js

@@ -78,6 +78,16 @@ exports.seed = async (knex) => {
 
     const userData = buildUserData();
 
+    if (userData.username) {
+      const existingUsernameUser = await knex('user_account')
+        .where('username', userData.username)
+        .first();
+
+      if (existingUsernameUser) {
+        throw new Error(`User with DEFAULT_ADMIN_USERNAME "${userData.username}" already exists.`);
+      }
+    }
+
     let userId;
     try {
       [{ id: userId }] = await knex('user_account').insert(