Prep: bring lists, polls, and to-dos

Every event has a Prep tab for the coordination that usually gets lost in the group chat:

• Bring list: post what the event needs (ice, chairs, dessert) and guests claim items.
• Polls: put questions to the group and let the answers settle themselves.
• Song requests: guests queue up what they want to hear.
• To-dos: an assignable checklist for hosts and helpers.

Guests who are Going or Maybe can contribute, so the prep stays with the people who are actually showing up.