How do you architect Svelte stores to minimize WebSocket re-renders?

Tests whether you understand Svelte store granularity and subscription semantics beyond basic usage. A great answer splits the monolithic store into domain-specific or feature-level stores, uses derived to create stable selectors that only notify when their extracted slice changes, and leverages readable or custom stores to encapsulate WebSocket mutation logic. Red flag: suggesting manual diffing in components, deep cloning in derived functions, or moving state to Context without solving the broadcast problem.