Get or create a StateManager with Gist-backed persistence. If a StateManager already exists (from sync init), returns it. If a token is provided and no manager exists, creates one with Gist backing. Falls back to sync initialization if no token is provided.
Important: This must be called (and awaited) before any command runs for
Gist mode to be active. It pre-sets the singleton so that subsequent
getStateManager() calls return the Gist-backed instance. If this is not
called first, getStateManager() will lazily create a local-only
StateManager and Gist checkpoints will be no-ops.
Optionaltoken: string
Core module exports Re-exports all core functionality for convenient imports