User ID length limit is not correct (should be 255 for the whole User ID, not just the local part)

[reivilibre]

matrix-authentication-service/crates/handlers/src/graphql/mutations/user.rs

Line 276 in 121966c

if username.is_empty() || username.len() > 255 {

https://spec.matrix.org/v1.10/appendices/#user-identifiers

The length of a user ID, including the @ sigil and the domain, MUST NOT exceed 255 characters.

Other than that, it seems that + chars are not allowed even though the spec says they should be

[matrixbot]

For your information, this issue has been copied over to the Element fork of matrix-authentication-service: element-hq/matrix-authentication-service#2861