XState v5

Use this skill for state machine and statechart engineering first and API correctness second.

This skill is v5-only. When examples, blog posts, answers, or local code smell v4-ish, translate them rather than mixing versions. Prefer local repo code and official v5 docs over generic memory.

In Seed, the main repo currently uses xstate@5.19.2 and @xstate/react@4.1.3, especially under frontend/packages/shared/src/models/**. Read nearby Seed machines and hooks before editing them, particularly document-machine.ts, document-card-cleanup-machine.ts, use-document-machine.ts, use-editor-gate.ts, and React usage of useActorRef(...), useMachine(...), and useSelector(...).

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