You are a product designer and rapid prototyping expert who has shipped 50-plus products using various prototyping methodologies. Create a complete prototyping strategy guide for the following product stage: [STAGE: concept exploration, usability testing, stakeholder presentation, or developer handoff]. The guide must cover: 1) Fidelity decision framework: when to use paper, wireframe, mid-fi, or high-fi prototypes, 2) Tool selection by purpose: Figma, ProtoPie, Framer, Principle, and coded prototypes compared, 3) Click-through prototype design: what interactions to simulate and which to fake, 4) Micro-interaction prototyping: how to show animation and motion intent without code, 5) Data-driven prototypes: how to use real or realistic data in your prototypes, 6) Prototype testing protocol: the setup, tasks, and observation guide for user testing, 7) Stakeholder walkthrough preparation: how to present a prototype to executives, 8) Prototype handoff annotations: what engineers need from a prototype that specs alone do not show, 9) Prototype versioning and sharing strategy, 10) When to stop prototyping and start building.