Migrate lint/format tooling to Ruff, update CI matrix, and stabilize cross-platform/firefox tests #4

	name: Lint and Format Check

	on: [push, pull_request]

	jobs:
	ruff:
	runs-on: ubuntu-latest

	steps:
	- uses: actions/checkout@v6

	- name: Set up Python
	uses: actions/setup-python@v6
	with:
	python-version: "3.13"

	- name: Install dev dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install -r requirements-dev.txt

	- name: Ruff format check
	id: format
	continue-on-error: true
	run: \|
	python -m invoke format --check

	- name: Ruff lint
	id: lint
	continue-on-error: true
	run: \|
	python -m invoke lint

	- name: Fail if any Ruff step failed
	if: always()
	run: \|
	echo "format outcome: ${{ steps.format.outcome }}"
	echo "lint outcome: ${{ steps.lint.outcome }}"
	if [ "${{ steps.format.outcome }}" != "success" ] \|\| [ "${{ steps.lint.outcome }}" != "success" ]; then
	exit 1
	fi

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