WASHINGTON — At least six million American kids will gain a stock portfolio next month when “Trump Accounts” are launched — and tens of millions more are able to sign up. The accounts will serve as an early-age 401 (k), granting children born during President Trump’s second term $1,000 in seed money, with parents or their employers able to make additional tax-free contributions of up to $5,000 per year into the accounts. Experts tell The Post that children – especially those eligible for the $1,