- Set 'git config windows.appendAtomically false' in hermes update
command (win32 only) and in install.ps1 after cloning. Fixes the
'fatal: unable to write loose object file: Invalid argument' error
on Windows filesystems.
- Fix venv pip fallback path: Scripts/pip on Windows vs bin/pip on Unix
- Gate .env encoding fix behind _IS_WINDOWS (no change to Linux/macOS)