IT11–IT13 mirror IT10 on the Linux platform branch, verifying:
- Xvfb workarounds coexist with SOCKS5 proxy mutation
- MSAA pin propagates through prefs translation on Linux
- _LINUX_GENERIC_FONT_FACTORS is prepended to per-font metrics
Tests use monkeypatch on sys.platform so they run on any host OS.
Verified green on Linux/WSL alongside the existing Windows tests.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>