v2.43.0 — The permission is never the wound

Inspired by Oleksandr Torlo's The Permission Was the Wound (2026): the danger of an agent isn't going rogue — it's doing exactly what it's permitted, irreversibly, at machine speed, with no human hesitation. This release makes the human↔autopilot boundary an enforced runtime invariant.

• reversible + blastRadius on every flow step — read/draft/check vs money-move/claim-submission/e-signing/fleet-change/tax-filing.
• The runtime refuses to execute an irreversible action autonomously — an irreversible step with no prior human checkpoint is blocked; a protected one runs only after the gate is signed (never auto-fired in a dry-run).
• validateFlow() + flow-runner.mjs <v> --validate — enforces irreversible ⟹ preceded by a gate and every autopilot names an accountable owner. All six verticals ship green.
• Accountable owner per autopilot — one named human answers for it, closing the confused-deputy / 'the AI did it' gap. Surfaced in the run trace and on each autopilot page.

Backward-compatible (new fields optional; all six flows already place irreversible actions after the human gate). 7 new tests — 30 in the flow-runner suite, 220 lib total.