Registration fields lack sufficient format validation and character limit restrictions.

Description

When entering data in the username field, there are no character limits but there are format restrictions, and no characters besides _ and - can be in the username field. The first name, last name, password, and email fields don’t have character limits or format restrictions.

Steps

1. Click on Sign Up
2. Enter data in the Runestone Registration fields

Expected Result

The registration fields should enforce character limits and format restrictions, providing users with feedback if incorrect data is entered.

Actual Result

Special characters and unicode characters are allowed to be entered when registering as a new user and there are no limits to how many characters can be entered in the registration fields.

Start from the Sign Up flow and inspect the Runestone Registration fields described in the issue. Review how username, first name, last name, password, and email input is currently validated. Done means each field enforces agreed format and length rules and gives feedback for invalid input.