fix : port fix

frontend/src/api/client.ts

@@ -1,6 +1,6 @@
 import type { User, UserCreate, Project, ProjectCreate, ProjectsResponse, ProjectAvailability, Task, TaskCreate, TasksResponse, MembersResponse, ActivityResponse } from '../types';
 
-const API_BASE = 'http://localhost:8000/api';
+const API_BASE = '/api';
 
 class ApiClient {
   private async request<T>(endpoint: string, options?: RequestInit): Promise<T> {