feat: Add optional display name to user profile with corresponding API and UI updates

backend/src/handlers/users.rs

@@ -28,6 +28,7 @@ pub struct CreateUserRequest {
 /// Request to update a user.
 #[derive(Deserialize)]
 pub struct UpdateUserRequest {
+    pub name: Option<String>,
     pub height_cm: Option<f32>,
     pub blood_type: Option<String>,
     pub birthdate: Option<String>,
@@ -41,6 +42,7 @@ pub struct UpdateUserRequest {
 pub struct UserResponse {
     pub id: i32,
     pub username: String,
+    pub name: Option<String>,
     pub role: String,
     pub height_cm: Option<f32>,
     pub blood_type: Option<String>,
@@ -85,6 +87,7 @@ pub async fn list_users(
         .map(|u| UserResponse {
             id: u.id,
             username: u.username,
+            name: u.name,
             role: role_map.get(&u.role_id).cloned().unwrap_or_default(),
             height_cm: u.height_cm,
             blood_type: u.blood_type,
@@ -130,6 +133,7 @@ pub async fn get_user(
     Ok(Json(UserResponse {
         id: u.id,
         username: u.username,
+        name: u.name,
         role: role_name,
         height_cm: u.height_cm,
         blood_type: u.blood_type,
@@ -211,6 +215,7 @@ pub async fn create_user(
     Ok(Json(UserResponse {
         id: inserted.id,
         username: inserted.username,
+        name: inserted.name,
         role: role_name,
         height_cm: inserted.height_cm,
         blood_type: inserted.blood_type,
@@ -246,6 +251,9 @@ pub async fn update_user(
     let now = Utc::now().naive_utc();
 
     let mut active: user::ActiveModel = existing.into();
+    if req.name.is_some() {
+        active.name = Set(req.name);
+    }
     if req.height_cm.is_some() {
         active.height_cm = Set(req.height_cm);
     }
@@ -291,6 +299,7 @@ pub async fn update_user(
     Ok(Json(UserResponse {
         id: updated.id,
         username: updated.username,
+        name: updated.name,
         role: role_name,
         height_cm: updated.height_cm,
         blood_type: updated.blood_type,

backend/src/models/user/user.rs

@@ -18,6 +18,9 @@ pub struct Model {
     /// Foreign key to roles table
     pub role_id: i32,
 
+    /// Display name (optional, separate from username)
+    pub name: Option<String>,
+
     // Profile fields
     /// Height in centimeters
     pub height_cm: Option<f32>,