Validate/restrict user names

[alopezlago]

website/routes/auth.js

Line 178 in 7f008c4

router.post('/signup', async (req, res) => {

There doesn't seem to be any validation done for newly created usernames. This can lead to a few problems:

• Names with spaces or other unusual characters that can cause breaks elsewhere
• Names with slurs

Consider restricting usernames to be alphanumeric (and maybe _) and, if possible, using a denylist to block inappropriate names.