After a 40-minute session helping plan a dinner party, the conversation has grown to 78,000 tokens. The history includes: (1) the user mentioning a guest has a severe shellfish allergy, (2) measurements for scaling recipes to 8 servings, (3) the user's clarification that "room temperature butter" means 68°F in their kitchen, and (4) general back-and-forth about meal timing and presentation. You need to implement context management before the window limit is reached. What approach best balances information preservation with token reduction?