What is the ruling on a wife returning to her husband after the marriage contract has been annulled in court by a default judgment, and she stipulates a condition for her return during the 'iddah (waiting period)?

If the judge rules for your divorce, then the divorce is an irreversible divorce (طلاق بائن), and the husband does not have the right to take you back except with a new contract. He is permitted to marry you during the iddah (waiting period) if it is a minor irreversible divorce (meaning it was not the last of the three pronouncements), and you may stipulate any permissible conditions you wish.