long, detailed marriage contracts can't save you in this situation either btw.
say you do get him to agree on you working whenever, and one day the situation arises that he doesn't like it and would like you to spend time with the kids/his parents/whatever reason. you could say that "no, it's in the marriage contract that i can work!" but obviously the outcome of that will leave one party resenting each other. i'm not saying not to have a good marriage contract, but realize that marriage doesn't work like business; whipping out that contract won't automatically make one spouse cease and desist
anyway, insha'Allah khair may we all have happy, fulfilling lives (both at home and if we wish, professionallly) that bring us closer to our spouses.