BLOG-86 refactor: update UserId struct to encapsulate user ID and improve access method

backend/feature/auth/src/framework/web/auth_middleware.rs

@@ -32,7 +32,13 @@ pub async fn auth_middleware(
     next.call(req).await
 }
 
-pub struct UserId(pub i32);
+pub struct UserId(i32);
+
+impl UserId {
+    pub fn get(&self) -> i32 {
+        self.0
+    }
+}
 
 impl FromRequest for UserId {
     type Error = Error;

backend/feature/auth/src/framework/web/auth_web_routes.rs

@@ -102,5 +102,5 @@ async fn logout_handler(session: Session) -> impl Responder {
 }
 
 async fn get_logged_in_user_handler(user_id: UserId) -> impl Responder {
-    HttpResponse::Ok().body(format!("Logged in user ID: {}", user_id.0))
+    HttpResponse::Ok().body(format!("Logged in user ID: {}", user_id.get()))
 }