application: auth bounded context (register, login)

crates/domain/src/models/user.rs

@@ -85,6 +85,13 @@ impl User {
     pub fn created_at(&self) -> DateTime<Utc> {
         self.created_at
     }
+
+    // -- Mutations --
+
+    /// Promote this user to admin.
+    pub fn promote_to_admin(&mut self) {
+        self.is_admin = true;
+    }
 }
 
 #[cfg(test)]