How Shared State Breaks Server-Side Rendering (And How to Fix It)

Server-rendered apps often use global state stores that become dangerous under concurrent requests—one user's data can leak into another's hydration payload through shared module variables. This classic SSR footgun affects not just Pareto but most state libraries and frameworks. Understanding the difference between process-level state (defineStore) and per-request state (defineContextStore) is critical for shipping secure SSR applications.