refactor: restructure application to CQRS, update api-types + presentation

- application: replace flat use_cases/ with identity/{commands,queries}/ and organization/commands/
- each use case now split into Command/Query struct + Handler struct
- api-types: add username to RegisterRequest/UserResponse, add CreateAlbumRequest/AlbumResponse
- presentation: update state, handlers, factory to use new handler types
- tests: restructured to match CQRS module layout, added get_profile tests

crates/api-types/src/requests.rs

@@ -1,5 +1,6 @@
 #[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
 pub struct RegisterRequest {
+    pub username: String,
     pub email: String,
     pub password: String,
 }
@@ -9,3 +10,8 @@ pub struct LoginRequest {
     pub email: String,
     pub password: String,
 }
+
+#[derive(Debug, serde::Deserialize, utoipa::ToSchema)]
+pub struct CreateAlbumRequest {
+    pub title: String,
+}

crates/api-types/src/responses.rs

@@ -4,6 +4,7 @@ use uuid::Uuid;
 #[derive(Debug, serde::Serialize, utoipa::ToSchema)]
 pub struct UserResponse {
     pub id: Uuid,
+    pub username: String,
     pub email: String,
     pub created_at: DateTime<Utc>,
 }
@@ -18,8 +19,30 @@ impl UserResponse {
     pub fn from_domain(user: &domain::entities::User) -> Self {
         Self {
             id: *user.id.as_uuid(),
+            username: user.username.clone(),
             email: user.email.to_string(),
             created_at: user.created_at,
         }
     }
 }
+
+#[derive(Debug, serde::Serialize, utoipa::ToSchema)]
+pub struct AlbumResponse {
+    pub id: Uuid,
+    pub title: String,
+    pub description: String,
+    pub creator_id: Uuid,
+    pub created_at: DateTime<Utc>,
+}
+
+impl AlbumResponse {
+    pub fn from_domain(album: &domain::entities::Album) -> Self {
+        Self {
+            id: *album.album_id.as_uuid(),
+            title: album.title.clone(),
+            description: album.description.clone(),
+            creator_id: *album.creator_user_id.as_uuid(),
+            created_at: *album.created_at.as_datetime(),
+        }
+    }
+}