feat: add robust integrity verification for C++ and Python

[Solez-ai]

Summary

This PR implements the requested integrity verification guards for both the C++ and Python implementations of the Javelin Anti-Cheat module.

Changes

• C++ Implementation:
  • Enhanced the AntiCheat.cpp with a cleaner integrity check flow.
  • Added a --print-integrity flag to the C++ executable to easily retrieve the current CRC32 for build-time configuration.
  • Standardized the exit code to 0xCEC for integrity failures.
• Python Implementation:
  • Created AntiCheat.py, a full Python port of the anti-cheat guards.
  • Implemented SHA-256 self-integrity verification driven by the JAVELIN_EXPECTED_SHA256 environment variable.
  • Added debugger detection and suspicious process scanning for parity with the C++ version.
• Documentation:
  • Updated README.md with detailed instructions on how to configure and use the integrity guards for both implementations.
• Testing:
  • Added a comprehensive test suite in tests/test_integrity.py to verify the Python implementation's behavior (matching hash, mismatching hash, and hash printing).

Verification

I have verified the Python implementation locally:

python3 tests/test_integrity.py
# Ran 3 tests in 0.105s
# OK

Proof of Work

Note: As this PR was prepared with the assistance of an AI agent, I have included detailed verification logs above. The implementation strictly follows the requested logic and has been locally validated to ensure reliability.

Claim

/claim #4