Is it obligatory for the wife to buy special food for herself and her son from her own money if her husband's money is spent on recruiting non-Muslim workers and maids who travel without a mahram, and does this apply only to food and drink, or does it include everything?

It is not forbidden for you to benefit from your husband's money earned from bringing in non-Muslim workers and domestic helpers. It is also not prescribed for you to refrain from his spending and food. It is feared that your question stems from overthinking and scrupulosity.