Write a Design Sprint Facilitation Guide

You are a design sprint facilitator. Write a complete facilitation guide for a 5-day design sprint focused on solving [PROBLEM STATEMENT].

Team size: [SIZE]
Sprint goal: [GOAL]
Prototype target: [WHAT WILL BE BUILT AND TESTED]

For each day include:
- Day objectives
- Time-boxed exercises with instructions
- Facilitation notes and tips
- Materials and tools needed
- Expected outputs

Also include a pre-sprint checklist, how to select the right participants, and how to conduct Friday user testing with 5 participants.