fusion‑cert v67: Rational, solver‑free certification artifacts for discrete‑time CBF safety in fusion operation

Exact-arithmetic, solver-free certification artifacts for “Algebraic certification of steady-state fusion operation with discrete-time control-barrier functions (CBFs)”. Package includes a single deterministic YAML with rational coefficients (no floats), an opcode witness ledger proving all claims (support-plane redundancy, Lawson L4/L5 floors, discrete-time CBF margins, baseline minima, KPI volume), a minimal Python verifier using exact fractions, and SHA-256 checksums. Reproduce by unzipping and running python3 verify.py → PASS. Scope: steady-state magnetic-confinement fusion(tokamak-like), device-portable via monotone adapters; no external data or simulators required.