fix: handle 204 No Content in DELETE responses

DELETE endpoints (deletePlan, deleteEntitlement, deleteMember) return
204 with empty body. handleApiResponse was trying to parse JSON from
empty response, causing: 'Unexpected end of JSON input'

Fix: Check for status 204 before calling response.json()
Return { success: true, data: undefined } for 204 responses

This resolves console error while maintaining successful delete operations.

src/lib/api/facility-admin.ts

@@ -33,6 +33,11 @@ import apiFetch from '@/src/utils/apiFetch';
  */
 async function handleApiResponse<T>(response: Response): Promise<FacilityAdminApiResult<T>> {
   if (response.ok) {
+    // Handle 204 No Content - DELETE endpoints return empty body
+    if (response.status === 204) {
+      return { success: true, data: undefined as T };
+    }
+
     const json = await response.json();
     // Flask returns { status: 'success', data: {...} }
     // Extract the actual data from the wrapper