Client-side domain folding is gone (RFC final: the host is the only
computation site): ProjectionCellSpec/fromEvent, ProjectionCellSet, the
SessionsService cell roster, and the Session event-dispatch projection hooks
all delete; Session.projections becomes the generic value store (manager-owned
via SessionOptions so frames landing before instantiation and the history
baseline converge on one row set), and installWindow only seeds the store from
a carried block. The cell specs retire with the machinery — the value store's
own spec owns the seq semantics now.
imccyu
913125294b