Factor the shared dev-shell toolchain into `basePkgs` + `baseHook`
so extra-tooling shells can extend it, then add a `docs` shell =
base + `pkgs.d2` (the diagram renderer our `.. d2::` sphinx
directive shells out to). Keeps `d2` OUT of the `default` shell so
casual dev envs stay lean.
Enter with `nix develop .#docs`, then build via `uv run --group
docs make -C docs html`.
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code
Based on the impure template from `pyproject.nix` and providing
a dev-shell for easy bypass-n-hack on nix(os) using `uv`.
Deats,
- include bash completion pkgs for devx/happiness.
- pull `ruff` from <nixpkgs> to avoid wheel (build) issues.
- pin to py313 `cpython` for now.
Gud Boi