React 19 & Modern Hooks Protocol

Author high-performance, maintainable React component trees.

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1. Server vs Client Components

1. Default to React Server Components (RSC) for data fetching, static rendering, and zero-bundle-size overhead.
2. Add 'use client' only at the leaf nodes requiring browser events (onClick, onChange), browser APIs, or stateful hooks.

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2. Hooks Discipline & Rules

1. Never call hooks conditionally or inside loops.
2. Keep useEffect strictly for synchronization with external non-React systems. Do not use useEffect to calculate derived state or trigger cascading renders.