domain: add cross-cutting value objects (SystemId, DateTimeStamp, Checksum, StructuredData)

crates/domain/src/entities/user.rs

@@ -1,17 +1,16 @@
 use chrono::{DateTime, Utc};
-use crate::value_objects::{Email, PasswordHash, Role, UserId};
+use crate::value_objects::{Email, PasswordHash, SystemId};
 
 #[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 pub struct User {
-    pub id: UserId,
+    pub id: SystemId,
     pub email: Email,
     pub password_hash: PasswordHash,
-    pub role: Role,
     pub created_at: DateTime<Utc>,
 }
 
 impl User {
-    pub fn new(id: UserId, email: Email, password_hash: PasswordHash) -> Self {
-        Self { id, email, password_hash, role: Role::User, created_at: Utc::now() }
+    pub fn new(id: SystemId, email: Email, password_hash: PasswordHash) -> Self {
+        Self { id, email, password_hash, created_at: Utc::now() }
     }
 }