Whether document is in instance's reactive watch-set — the
reverse of subscriptionDocumentsForInstance. Both derive from
the shared watch-ref collector, the single source of truth, so "which docs does
this instance watch" and "which instances watch this doc" stay in lockstep
— the same way hydrateSnapshot's load-set does. Matching is on the
resource-qualified GDR URI, so a cross-dataset subject (dataset:A:ds:doc)
never matches a same-id doc in another resource (dataset:B:ds:doc).
A non-reactive, content-change-driven runtime uses this to decide whether a
changed document should re-tick an instance it does not hold in memory.
Whether document is in instance's reactive watch-set — the reverse of subscriptionDocumentsForInstance. Both derive from the shared watch-ref collector, the single source of truth, so "which docs does this instance watch" and "which instances watch this doc" stay in lockstep — the same way
hydrateSnapshot's load-set does. Matching is on the resource-qualified GDR URI, so a cross-dataset subject (dataset:A:ds:doc) never matches a same-id doc in another resource (dataset:B:ds:doc).A non-reactive, content-change-driven runtime uses this to decide whether a changed document should re-
tickan instance it does not hold in memory.