v1.43.0

• Compare two stored plan slots: plan-state --compare <slotA> <slotB> (surfaced through
  /stereo:plan-state) renders both slots' review metadata side by side plus a unified line diff
  of the stored plan texts from a new dependency-free capped LCS — per-side preflights (2000
  effective lines, one million UTF-16 code units) run before any allocation-scale work, an empty
  side normalizes to zero lines, and the hunk format is pinned byte-exactly by tests. The JSON
  payload is metadata-only; each full plan stays reachable per slot via --json --slot or
  --open
• Complete the alternating-vendor defaults at the build seats: claude:opus implements in the
  contained file-edit agent and codex:sol gates the diff, so every handoff crosses ecosystems —
  Claude plans and builds, Codex challenges the plan and gates the diff
• Make the implementer resolution honest under any model mix: stored-plan and plan-review payload
  models never resolve the implementer (explicit flag > workspace default > built-in), a Codex
  implementer resumes the stored review thread only when it is the model that produced it, a
  same-model implementer/reviewer pairing from the built-in default substitutes the other
  ecosystem's review gate (explicit or workspace-configured self-review is honored but called
  out), and --fresh is reported as inert for a Claude-routed implementer