feat(dimentorin): mentor stats endpoint public - total sessions, unique mentees, avg rating

- GET /mentors/{id}/stats (public, no auth)
- resolve mentor profile id -> user id in get_mentor_sessions (FK uses app_users.id)

imphnen-dimentorin/src/sessions/infrastructure/http/routes.rs

@@ -1,6 +1,7 @@
 use super::handlers::{
-	get_mentor_availability, get_mentor_sessions, get_my_sessions, post_book_session,
-	post_submit_feedback, put_update_session_status,
+	get_mentor_availability, get_mentor_sessions, get_mentor_stats,
+	get_my_sessions, post_book_session, post_submit_feedback,
+	put_update_session_status,
 };
 use crate::sessions::application::SessionServiceImpl;
 use crate::sessions::domain::SessionService;
@@ -14,14 +15,16 @@ use sea_orm::DatabaseConnection;
 use std::sync::Arc;
 
 fn build_service(db: DatabaseConnection) -> Arc<dyn SessionService> {
-	let repo = Arc::new(PostgresSessionRepository::new(db));
-	Arc::new(SessionServiceImpl::new(repo))
+	let db_arc = Arc::new(db);
+	let repo = Arc::new(PostgresSessionRepository::new(Arc::clone(&db_arc)));
+	Arc::new(SessionServiceImpl::new(repo, db_arc))
 }
 
 pub fn sessions_public_routes(db: DatabaseConnection) -> Router {
 	let service = build_service(db);
 	Router::new()
 		.route("/mentors/{id}/availability", get(get_mentor_availability))
+		.route("/mentors/{id}/stats", get(get_mentor_stats))
 		.layer(Extension(service))
 }