Add Generate Prime Number operation

[p-leriche]

Description

Generates cryptographically random probable prime numbers using the Miller-Rabin primality test, to teaching grade (7 rounds) or crypto grade (40 rounds)

Changes

• Add GeneratePrime.mjs operation
• Update BigIntUtils.mjs to include modPow helper function
• Update Categories.json to include Generate Prime Number in Crypto category

Functionality

Generates random prime numbers of specified bit length (2-4096 bits) with configurable certainty levels:

Primality guarantee:

• For numbers ≤ 3,317: Deterministic (guaranteed prime)
• Crypto grade (40 rounds): Probability of composite < 2^-80 (~1 in 10^24)
• Standard (7 rounds): Probability of composite < 2^-14 (~1 in 16,000)

Use Cases

• RSA key generation (typically 1024 or 2048-bit primes)
• Diffie-Hellman key exchange
• Elliptic curve cryptography
• General cryptographic applications requiring large primes

Features

• Cryptographically secure random number generation
• Configurable bit length (2-4096 bits)
• Crypto grade vs. teaching grade (for educational purposes)
• Output in decimal or hexadecimal format
• Fully pipeable output (just the prime number)

Dependencies

Depends on BigIntUtils PR #2205

This operation uses modPow from the shared BigIntUtils library.

Testing

• Tested with small bit lengths (8, 16, 32 bits)
• Tested with cryptographic bit lengths (512, 1024, 2048 bits)
• Tested both crypto grade and standard modes
• Built successfully with npm run build