feat: add baseline Python anti-cheat monitor

[KaannKara]

Summary

• add anti_cheat.py for the Python runtime path with debugger and suspicious-process checks
• add unit coverage for process-name normalization, debugger priority, suspicious process detection, and clean runs
• keep the C++ client buildable on non-Windows CI while preserving Windows debugger/process checks and fixing the invalid CRC exit literal

Fixes #2
/claim #2

Tests

• python3 -m py_compile anti_cheat.py tests/test_anti_cheat.py
• python3 -m unittest discover -s tests -v
• python3 anti_cheat.py
• c++ -std=c++17 -Wall -Wextra -pedantic AntiCheat.cpp -o /tmp/javelin-anticheat-check && /tmp/javelin-anticheat-check
• git diff --check