Fix mobile tracked as regular files (not submodule)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

mobile/src/queries/useRegistrations.ts

@@ -0,0 +1,30 @@
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
+import { registrationsApi } from '../api/registrations.api';
+import { RegistrationCreate } from '../types/registration.types';
+
+export function useMyRegistrations() {
+  return useQuery({
+    queryKey: ['registrations', 'my'],
+    queryFn: registrationsApi.myRegistrations,
+  });
+}
+
+export function useSubmitRegistration() {
+  const queryClient = useQueryClient();
+  return useMutation({
+    mutationFn: (data: RegistrationCreate) => registrationsApi.submit(data),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['registrations', 'my'] });
+    },
+  });
+}
+
+export function useWithdrawRegistration() {
+  const queryClient = useQueryClient();
+  return useMutation({
+    mutationFn: (id: string) => registrationsApi.withdrawRegistration(id),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ['registrations', 'my'] });
+    },
+  });
+}