amicode_verify v2: typed rollout-spec referee backend (replaces the bespoke re-rollout)

[aarontrowbridge]

Roadmap context: vault plan `plan-20260812-142100-problemspecs-issimo-roadmap` (W2.5); master spec §"rollout kind" + "Referee independence". Depends on #340 (the originating control spec must exist to derive the referee from).

What changes

Today free-tier verification is a bespoke re-rollout: `verify_rollout.jl` re-implements goal reconstruction from `system_verify.jld2`, and `amicode_verify` records agree/disagree from an unstructured comparison. Piccolo.Specs Phase 1 shipped the typed machinery for exactly this: the `rollout` kind, the `referee_rollout(control_spec, run)` constructor (strictly finer in every resolution axis, different integrator family, forge-proof `[referee]` block re-validated at parse time), and `Verdict`/`Agree`/`Disagree` as types.

Tasks

• `amicode_verify` v2 (opencode-plugin): derive the rollout spec from the run's retained control spec (`result.toml [params].spec` — the runner persists it), set `input.pulse` to the run's `pulse-*.jld2`, `report.fidelity` against the original goal, run synchronously.
• This is the master spec's scoped exception to the never-launches invariant: rollouts are bounded, seconds-scale, produce no run_dir. The invariant continues to hold for `control`/`tuning`.
• Record the typed verdict (both fidelities as witness) instead of an unstructured agree/disagree; a rollout without a valid `[referee]` block yields no verdict by construction — surface that, don't mint one.
• Retire the `system_verify.jld2` snapshot from the free-tier skeleton once the typed path is proven on it (the skeleton's CONTRACT block emits it today; that's the migration seam).

Acceptance

• Master-spec success criterion 6: a rollout spec derived from a completed control run reproduces the run's re-rolled fidelity to 1e-10.
• A forged/inconsistent `[referee]` block fails validation (testitem/vitest); a hand-written rollout spec without `[referee]` runs but its result carries no `verdict`.

[jeonghun-jj-lee]

Closing — the verification contract is wired (amicode_verify tool with agree/fidelity_reported/fidelity_rerolled). The typed rollout-spec referee is live.