Add ProofLiveReal (highest level, no driver yet) and enforce it at
execute time: rotate --execute only runs drivers with proof >= LIVE-VM
(MinExecuteProof). MOCK-ONLY/UNPROVEN drivers are skipped before any
provider call unless --allow-mock-proven is passed. ExecuteResult gains
Skipped/SkipReason; the CLI reports and audit-logs skips separately from
failures. Closes the last structural gap where an emulator-only driver
could touch a real credential unattended. Covered by execute_gate_test.go.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
leetcrypt