build: migrate to uv, add ruff/ty, format all files

[FIrgolitsch]

PR A — Build Tooling & Formatting

Migrates the project build system to modern Python tooling and applies consistent formatting across the entire codebase.

Changes

Build system migration (setup.py → uv + pyproject.toml)

• Full pyproject.toml with project metadata, dependencies, optional GPU deps, script entries for all existing scripts
• uv.lock for reproducible dependency resolution
• Delete setup.py, requirements.txt, requirements-pytest.txt

Linting & formatting (ruff + ty)

• [tool.ruff] config: target py312, line-length 127, select E/F/W/I/UP/B/RUF/SIM/C4/PIE/PTH
• [tool.ruff.lint.isort] with _thread_config section ordering
• [tool.ty] config: linumpy-only, py312, cupy/cupyx/numba → Any, relaxed overrides for tests and GPU modules
• .pre-commit-config.yaml: ruff-format, ruff lint (--fix), ty (advisory/non-blocking)
• ruff format applied to all 122 Python files
• ruff check --fix applied (341 auto-fixes: import sorting, f-strings, type upgrades, etc.)

CI & Docker

• .github/workflows/python-app.yml updated: astral-sh/setup-uv@v5, uv sync, uv run ruff, uv run ty, uv run pytest
• Dockerfile updated for uv (replaces pip install)

Other

• linumpy/py.typed marker file
• [dependency-groups] dev: ruff, ty, pytest, pytest-cov, pytest-console-scripts, pre-commit

Notes

• 323 pre-existing lint warnings remain (PTH, SIM, E501, etc.) — to be addressed in future PRs
• Script entries in [project.scripts] limited to scripts currently on main; later PRs will add their own entries
• This PR is a prerequisite for all subsequent feature PRs in the split plan