refactor(ports): CQRS split — UserRepository = UserReader + UserWriter supertrait

crates/domain/src/ports.rs

@@ -45,10 +45,16 @@ pub trait EventConsumer: Send + Sync {
 }
 
 #[async_trait]
-pub trait UserRepository: Send + Sync {
+pub trait UserReader: Send + Sync {
     async fn find_by_id(&self, id: &UserId) -> Result<Option<User>, DomainError>;
     async fn find_by_username(&self, username: &Username) -> Result<Option<User>, DomainError>;
     async fn find_by_email(&self, email: &Email) -> Result<Option<User>, DomainError>;
+    async fn list_with_stats(&self) -> Result<Vec<UserSummary>, DomainError>;
+    async fn count(&self) -> Result<i64, DomainError>;
+}
+
+#[async_trait]
+pub trait UserWriter: Send + Sync {
     async fn save(&self, user: &User) -> Result<(), DomainError>;
     async fn update_profile(
         &self,
@@ -59,10 +65,13 @@ pub trait UserRepository: Send + Sync {
         header_url: Option<String>,
         custom_css: Option<String>,
     ) -> Result<(), DomainError>;
-    async fn list_with_stats(&self) -> Result<Vec<UserSummary>, DomainError>;
-    async fn count(&self) -> Result<i64, DomainError>;
 }
 
+/// Combined supertrait — `AppState.users` stays `Arc<dyn UserRepository>`.
+/// Blanket impl: any type implementing both sub-traits gets `UserRepository` for free.
+pub trait UserRepository: UserReader + UserWriter {}
+impl<T: UserReader + UserWriter> UserRepository for T {}
+
 #[async_trait]
 pub trait ThoughtRepository: Send + Sync {
     async fn save(&self, thought: &Thought) -> Result<(), DomainError>;