Add generateAllChallenges API function

src/api/admin.ts

@@ -74,6 +74,14 @@ export async function deleteChallenge(id: string) {
   return data;
 }
 
+export async function generateAllChallenges(date: string) {
+  const { data } = await apiClient.post(
+    '/admin/daily-challenges/generate-all',
+    { date },
+  );
+  return data;
+}
+
 export interface RetroactiveAchievementsResult {
   totalAwarded: number;
   usersAffected: number;