What problem does it solve? Svelte and SvelteKit apps using the Themis state library need consistent rules for wiring the Store class, creating selector readables, dispatching actions, and migrating legacy Svelte stores to Redux slices without lifecycle crashes or duplicated state ownership. ## Core Features & Use Cases - Routing Index: Directs frontend tasks with concrete Svelte/SvelteKit evidence to the correct leaf skills for selectors, component integration, Store lifecycle, and migration. - Selector Lifecycle Guardrails: Defines the three selector call modes (component-init readable, .select(state) one-shot reads, .effect() in sagas) to prevent lifecycle_outside_component crashes. - Migration Playbook: Provides an ordered workflow to convert writable/derived stores and $state/$derived runes into Redux slices, selectors, and sagas with cleanup verification. - Use Case: When adding a shared todo list across SvelteKit routes, the skill routes you to core policy, state-integrity, actions, reducers, and selectors guidance so the slice has canonical owners and passes architecture validation. ## Quick Start Ask the agent to wire a Themis Store into a SvelteKit root layout and migrate an existing writable store into a Redux slice with selectors and a saga.