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/pages/platform/components/EditPlatformUserModal.tsx

@@ -91,7 +91,7 @@ const EditPlatformUserModal: React.FC<EditPlatformUserModalProps> = ({
   // Update mutation
   const updateMutation = useMutation({
     mutationFn: async (data: any) => {
-      const response = await apiClient.patch(`/api/platform/users/${user.id}/`, data);
+      const response = await apiClient.patch(`/platform/users/${user.id}/`, data);
       return response.data;
     },
     onSuccess: () => {