BLOCKER 1 (bootstrap.py): Replace bash dirname/while loop in _claude_settings()
with a cross-platform python3 -c one-liner using pathlib.Path.parents. The bash
loop broke on Windows because root is 'C:\' not '/'. Python pathlib handles all
OS path separators correctly.
BLOCKER 2 (setup.sh): Add OS detection (IS_WINDOWS via OSTYPE/uname). On Windows
(Git Bash/MSYS2/Cygwin), skip the sudo ln -sf symlink step and print manual
PATH-extension instructions for PowerShell, CMD, and Git Bash. Also make venv
activation OS-aware (Scripts/activate on Windows, bin/activate elsewhere).
BLOCKER 3 (setup.py): New cross-platform Python installer at repo root. Does
everything setup.sh does — create venv, install editable, verify entry points,
seed secrets dir, .env, registry, bootstrap branch identity files — and works
natively on Windows without Git Bash. Uses sys.executable (no python3 vs python
ambiguity), pathlib throughout, and prints PATH instructions on Windows instead
of attempting symlink creation.
Closes#261.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>