feat: add discriminator and display name fields

crates/delta/src/util/regex.rs

@@ -1,12 +1,17 @@
 use once_cell::sync::Lazy;
 use regex::Regex;
 
+/// Regex for valid display names
+///
+/// Block zero width space
+/// Block newline and carriage return
+pub static RE_DISPLAY_NAME: Lazy<Regex> = Lazy::new(|| Regex::new(r"^[^\u200B\n\r]+$").unwrap());
+
 /// Regex for valid usernames
 ///
 /// Block zero width space
 /// Block lookalike characters
-pub static RE_USERNAME: Lazy<Regex> =
-    Lazy::new(|| Regex::new(r"^[^\u200BА-Яа-яΑ-Ωα-ω@#:\n\r\[\]]+$").unwrap());
+pub static RE_USERNAME: Lazy<Regex> = Lazy::new(|| Regex::new(r"^(\p{L}|[\d_.-])+$").unwrap());
 
 /// Regex for valid emoji names
 ///