feat: add SHA-256 integrity verification for C++ and Python paths

[yuliuyi717-ux]

/claim #4

This implements integrity verification for both paths described in #4.

What changed:

• C++ (AntiCheat.cpp)
  • kept optional CRC32 self-check (JAVELIN_EXPECTED_CRC32)
  • added optional SHA-256 self-check for running executable (JAVELIN_EXPECTED_SHA256)
  • guarded non-zero exits on mismatch for CRC and SHA checks
• Python (anti_cheat.py)
  • added SHA-256 script verification against JAVELIN_EXPECTED_SHA256
  • fail-closed guarded exit on mismatch
• Docs (README.md)
  • added setup instructions for expected hash values and usage for both implementations
• Tests (tests/test_integrity.py)
  • matching hash pass
  • mismatch fail
  • missing hash bypass
  • invalid hash format fail
  • tampered file detection
  • guarded non-zero exit on mismatch

Validation run:

• python3 -m unittest discover -s tests -p "test_*.py"
• python3 -m py_compile anti_cheat.py

Note:

• C++ source was updated in a Windows-compatible way (bcrypt API), but C++ runtime validation was not executed in this macOS environment.

[yuliuyi717-ux]

Hey folks, gentle bump on #12 (SHA-256 integrity verification for both C++ and Python paths). It’s been open for a few days, and I’d really appreciate a review when you have time. Happy to update anything needed—thanks!

[yuliuyi717-ux]

Quick follow-up on #12. The SHA-256 integrity verification updates for both C++ and Python paths are in place. If you want any adjustment to fit project conventions, I can update quickly. Appreciate a review when you have time.

[yuliuyi717-ux]

Hi maintainers, just a gentle follow-up on this PR adding SHA-256 integrity verification for both the C++ and Python paths. When you have a moment, could you please take a look and share any feedback? Happy to make any updates needed. Thanks!