unwatched method
Called when a node no longer has any subscribers.
For non-mutable nodes (like effects), stops them completely. For mutable nodes (like signals), marks them as dirty and clears their dependencies for lazy re-evaluation.
Implementation
@override
void unwatched(ReactiveNode node) {
if ((node.flags & ReactiveFlags.mutable) == ReactiveFlags.none) {
stop(node);
} else if (node.depsTail != null) {
node.depsTail = null;
node.flags =
17 /*ReactiveFlags.mutable | ReactiveFlags.dirty*/ as ReactiveFlags;
purgeDeps(node);
}
}