bind

Rebind every live entry to a new ThreadStream (or detach when thread == null).

Each live entry has its current runtime disposed (best-effort) and its store reset to entry.initial so consumers see a clean slate during the swap. When thread != null, a fresh runtime is opened against the new thread.

Critically the StreamStore instance is preserved across the rebind: framework subscribers (e.g. React's useSyncExternalStore) keep observing the same store reference, so their subscriptions survive the swap.

No-op when called with the currently bound thread.