group-hook: on-load, re-establish subscriptions
For every item in the synced map that doesn't have a matching outgoing
subscription, re-establish the subscription we expect to have.
++ on-save !>(state)
++ on-load
|= old=vase
- `this(state !<(state-zero old))
+ ^- (quip card _this)
+ :_ this(state !<(state-zero old))
+ %+ murn
+ ~(tap by synced)
+ |= [=path =ship]
+ ^- (unit card)
+ =/ =wire
+ [(scot %p ship) %group path]
+ =/ =term
+ ?: =(our.bowl ship)
+ %group-store
+ %group-hook
+ ?: (~(has by wex.bowl) [wire ship term])
+ ~
+ `[%pass wire %agent [ship term] %watch [%group path]]
+ ::
++ on-leave on-leave:def
++ on-peek on-peek:def
++ on-arvo on-arvo:def
