v2.1.0 — the walk: many actions as one correlated route

[2.1.0] - 2026-08-25

Added

• Layer 2 — the walk: many actions as one correlated route. beginWalk()
  admits a PLAN up front and executes it with no model call between steps,
  answering with a MANIFEST — ran, refused, never-reached, per row — because a
  screen action cannot be rolled back, so partial execution must be legible
  rather than summarized as "failed". Admission refuses from declarations
  alone, before anything runs: a step whose decisionOwner the walking
  principal does not own ("an agent may not pre-plan a decision it does not
  own"), a principal outside mayInvoke ("refused at plan time rather than at
  step three of a half-executed screen"), and a carry whose producer
  declares no produces — a carried value must come from a declared output,
  never from whatever a handler happened to return. Execution re-derives every
  step's offer at its own turn: batched is not blind, and a guard that stopped
  holding mid-plan is a refused row with L1's own teaching sentence. One turn,
  one walk, MANY plans — a refused step means the caller replans under the
  same walk id, and walk.record() holds the route actually taken. L2
  introduces no primitive L1 lacks; the walk identity is a correlation, not a
  concept.