By: ValentinHirschi <valentin.hirschi@gmail.com>
feat: refine bilinear integer exceptional domains exactly Use native Symbolica integer factorization and exhaustive signed divisors with preserved parent constraints and atomic budget failure. Release core gate: 2385 passed, zero failed, 32 existing ignored. Independently audited mathematics and implementation; formerly unsupported bilinear test fixtures replaced with genuine Pell exceptions without weakening assertions.