Add cachix/git-hooks.nix input and wire basedpyright, ruff,
ruff-format, and commitizen hooks into flake checks and devShell.
The basedpyright hook runs against a Nix-built venv so imports
resolve correctly in the sandbox.
Expose homeManagerModules.bulkgen and homeManagerModules.default
from the flake. The module provides programs.bulkgen.enable and
programs.bulkgen.package options, adding bulkgen to home.packages
when enabled.