DotContext

The causal history of a replica: every Dot it has ever witnessed, live or already removed. It is the memory that outlives a delete — that is what lets a merge tell "I saw that dot and dropped it on purpose" from "I just haven't seen it yet".

Stored compactly: the contiguous prefix per replica is a version vector (vv: replica → highest contiguous seq), and any non-contiguous dots wait in a cloud until the gaps before them fill, at which point they compact into the vector. The cloud is required because kuilt fabrics reorder and duplicate frames, so dots can arrive out of order.

It is itself a Quilted: piece is the join (union of both histories). Equality is canonical — compaction pushes the cloud as far into the vector as possible and drops already-covered dots — so two contexts with the same causal history are structurally equal, which the conformance laws rely on.