🧪 Wall-Sun-Sun Prime (Fibonacci-Wieferich Prime) Tester

Definition: A prime p > 5 is Wall–Sun–Sun (Fibonacci-Wieferich) if p² divides F_{p − ε} where ε = (5/p) Legendre symbol.
• ε = +1 if p ≡ ±1 (mod 5) → check F_p−1 ≡ 0 mod p²
• ε = −1 if p ≡ ±2 (mod 5) → check F_p+1 ≡ 0 mod p²
No such primes are known (searched far beyond 10¹⁴); expect “NO” every time.

Auto-Test checks these small/interesting primes: small ones, Fibonacci primes, and known Wieferich primes (1093, 3511).