refactor(frontend): Remove '/api' prefix from all API calls to align with backend URL convention

- Updated all API endpoint strings in 'frontend/src' (via sed and manual fixes) to remove the '/api/' prefix.
- Manually fixed 'Timeline.tsx' absolute URLs to use the 'api' subdomain and correct path.
- Manually fixed 'useAuth.ts' logout fetch URLs.
- Updated 'HelpApiDocs.tsx' sandbox URL.
- This change, combined with the backend URL update, fully transitions the application to use subdomain-based routing (e.g., 'http://api.lvh.me:8000/resource/') instead of path-prefix routing (e.g., 'http://api.lvh.me:8000/api/resource/').

frontend/src/components/Schedule/Timeline.tsx

@@ -39,7 +39,7 @@ export const Timeline: React.FC = () => {
     const { data: resources = [] } = useQuery({
         queryKey: ['resources'],
         queryFn: async () => {
-            const response = await axios.get('http://lvh.me:8000/api/resources/');
+            const response = await axios.get('http://api.lvh.me:8000/resources/');
             return adaptResources(response.data);
         }
     });
@@ -47,7 +47,7 @@ export const Timeline: React.FC = () => {
     const { data: backendAppointments = [] } = useQuery({ // Renamed to backendAppointments to avoid conflict with localEvents
         queryKey: ['appointments'],
         queryFn: async () => {
-            const response = await axios.get('http://lvh.me:8000/api/appointments/');
+            const response = await axios.get('http://api.lvh.me:8000/appointments/');
             return response.data; // Still return raw data, adapt in useEffect
         }
     });