Add fgaussian_jacobian_f64_ext.c #75

	name: CI

	on:
	push:
	branches: [ main ]
	pull_request:
	branches: [ main ]

	jobs:
	build-and-test:
	runs-on: ubuntu-latest

	strategy:
	matrix:
	# Quote versions so YAML doesn't parse e.g. 3.10 as a float (3.1).
	python-version: ['3.13']

	steps:
	- name: Checkout repository
	uses: actions/checkout@v4

	- name: Set up Python
	uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python-version }}

	- name: Upgrade pip
	run: python -m pip install --upgrade pip

	- name: Install build/test dependencies
	run: \|
	python -m pip install numpy pytest setuptools wheel

	- name: Install Python linter (ruff)
	run: python -m pip install ruff

	- name: Run Python linter (ruff)
	run: python -m ruff check .

	- name: Setup Node for Markdown linting
	uses: actions/setup-node@v4
	with:
	node-version: '18'

	- name: Install markdownlint-cli
	run: npm install -g markdownlint-cli

	- name: Run Markdown linter
	run: \|
	# Use repository-level config if present, otherwise use defaults
	if [ -f .markdownlint.json ]; then
	markdownlint -c .markdownlint.json "*/.md"
	else
	markdownlint "*/.md"
	fi

	- name: Build C extensions in-place
	run: python3 setup.py build_ext --inplace

	- name: Run tests
	run: python -m pytest -q

	- name: Quickstart smoke test
	# Run the smoke test from the repo root; require PYTHONPATH so the
	# in-place-built extension modules are importable.
	run: \|
	PYTHONPATH=src python3 scripts/quickstart_smoke.py

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