Add account connections, guild wallets and admin fixes [skip ci]

panel/server/src/auth.rs

@@ -127,6 +127,7 @@ pub async fn create_user(
     role: &str,
     status: &str,
 ) -> AppResult<i64> {
+    crate::store::check_username(state, username).await?;
     let hash = hash_password(password)?;
     sqlx::query_scalar(
         "INSERT INTO users (username, password_hash, email, role, status, created_at, uuid) VALUES (?, ?, ?, ?, ?, ?, ?) RETURNING id",