Disproof #45 verification script architecture: 12,856 assertions default, 1,284 fast mode

The verify_conj143.py script includes: exact characteristic polynomial factorization over ℤ, Sturm sequence for isolating positive roots, rational interval bounds proving variance strictly above size/avgdist, and exhaustive verification across all 261,080 connected graphs order ≤9. Default mode runs 12,856 assertions requiring sympy + scipy + nauty; --fast mode runs 1,284 assertions. The rational certificate is self-contained — no floating-point uncertainty.