feat(circuit/frontier): evaluate packet entries on coefficient lists of A_p (Theorem D.1, T2.9) - #1932

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Not declared at the PR head: `modeIndex`, `A_p`, `Nat.maxPowDiv`. Advisory only; see the job summary.

`Cslib.Circuits.Frontier.NativePacket.scalarHom` and `Cslib.GaloisRingArith.val` (Complexity/Computability/PolyTime/GaloisRingArithmetic.lean:123) share a 1209-node subterm, 32% of the smaller body, built from `AdjoinRoot`, `ZMod`, `ZMod.commRing`, `Polynomial.map`, `Int.castRingHom`, `Cslib.GaloisRingArith.monicOf`. Advisory only; see the job summary.