zorch.sumcheck.jagged

Scheme-agnostic jagged-sumcheck plumbing.

The reusable machinery for a fixed-width, size-invariant jagged sumcheck round engine, factored out of the LogUp-GKR prover so any jagged sumcheck consumer (e.g. a jagged zerocheck) can share it:

• buffers — fixed-width cap buffers + the donated layer-entry pool.
• fs — the per-round Fiat-Shamir hop (observe/squeeze/fold).
• layout — the numpy segment-gather / even-prepad recurrences.
• schedule — the row_counts -> gather/live/re-pad round schedule.
• types — RoundWidthCaps, the interpolation constants, the round schedule.
• rounds — the generic round-coefficient helpers (bind, Gruen coeffs).

The LogUp-specific combine (the four n0/n1/d0/d1 planes + lam + LogupSummand) stays in zorch.logup_gkr, which imports this package one-way.