Expand description
The in-memory graph loaded from links_current, and its loader (§5.4).
A Subgraph is derivative state (Doctrine VI): every field is re-derivable
from the ledger, nothing here is authoritative, and dropping one loses
nothing. That is what lets analytics run on a snapshot without a third clock
— the graph is the topology as of one instant, and the instant is the
caller’s now_ts, not a property of the structure.