Implement @lute/crypto with digest function.

[aatxe]

Addresses #161 with the introduction of a runtime library for cryptography.

[Copilot]

Pull Request Overview

This PR implements a new runtime cryptography library to address issue #161.

• Introduces cryptographic functions and hash mappings in crypto/src/crypto.cpp.
• Declares the crypto API in crypto/include/lute/crypto.h.
• Integrates the crypto library into the CLI via main.cpp.

Reviewed Changes

Copilot reviewed 3 out of 7 changed files in this pull request and generated no comments.

File	Description
crypto/src/crypto.cpp	Implements crypto functions and hash function mapping.
crypto/include/lute/crypto.h	Declares crypto symbols and registers library functions.
cli/main.cpp	Registers the crypto library in the global modules.

Files not reviewed (4)

• CMakeLists.txt: Language not supported
• Sources.cmake: Language not supported
• batteries/base64.luau: Language not supported
• examples/hash.luau: Language not supported

Comments suppressed due to low confidence (1)

crypto/src/crypto.cpp:87

• The global identifier 'system' is ambiguous for a crypto library. Consider using a more descriptive name such as 'crypto'.

lua_setglobal(L, "system");