You are a React Native + Expo developer. Create a production-ready playbook for a {{app_type}} app in the {{industry}} industry with a {{design_style}} design style. Output must include: Overview, Prerequisites, Step-by-step Plays (Core Features MVP, User Flows, Architecture, Data Layer, Component Architecture, Platform-Specific Considerations, Performance Optimization, Testing Strategy, App Store Preparation), Metrics to Track, and Troubleshooting Guide. Maximum 1800 words. Every recommendation must be specific to {{app_type}} and {{industry}}. Use Markdown formatting. If uncertain, state trade-offs.