feat(cursor): add native PowerShell hooks on Windows

[MfDevNet]

Detect the host OS during Cursor hook installation and generate .ps1 scripts with PowerShell-native JSON output on Windows, while keeping the existing Bash hooks unchanged on Linux and macOS. hooks.json now invokes PowerShell with -ExecutionPolicy Bypass on Windows.

Pull Request

Linked issue

Closes #

What & why

How it was tested

uv run pytest tests/ --tb=short -q
uv run ruff check code_review_graph/
uv run mypy code_review_graph/ --ignore-missing-imports --no-strict-optional

Checklist

• Tests added for new functionality
• All tests pass: uv run pytest tests/ --tb=short -q
• Linting passes: uv run ruff check code_review_graph/
• Type checking passes: uv run mypy code_review_graph/ --ignore-missing-imports --no-strict-optional
• Lines are at most 100 characters
• Docs updated where behavior changed (README, docs/, docstrings)