phase 1: add Gemfile pinned to github-pages for reproducible local builds #12

	name: site-health

	on:
	pull_request:
	paths:
	- '*.html'
	- '*.md'
	- '_layouts/**'
	- '_includes/**'
	- '_config.yml'
	- '_data/**'
	- '_posts/**'
	- 'images/**'
	- 'css/**'
	- 'js/**'
	- 'Gemfile'
	- 'Gemfile.lock'
	- 'lychee.toml'
	- '.html5validator.yaml'
	schedule:
	# Weekly Monday 9am UTC, matching update-publications cadence.
	- cron: '0 9 * * 1'
	workflow_dispatch:

	jobs:
	site-health:
	runs-on: ubuntu-latest

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

	- name: Set up Ruby
	uses: ruby/setup-ruby@v1
	with:
	ruby-version: '3.3'
	bundler-cache: true

	- name: Build site
	run: bundle exec jekyll build

	- name: Check links with lychee
	id: lychee
	uses: lycheeverse/lychee-action@v2
	with:
	# --exclude-path takes a regex matched against file paths.
	# Skip legacy blog posts (deferred to a content-cleanup phase)
	# and old top-level dated posts.
	args: >-
	--config ./lychee.toml
	--no-progress
	--root-dir ${{ github.workspace }}/_site
	--exclude-path _site/blog
	--exclude-path _site/2015
	_site
	output: lychee-report.md
	fail: true

	# On failure, post the lychee report as a sticky PR comment so
	# the specific failing URLs are easy to see without digging
	# through job logs. Sticky = updates in place rather than piling up.
	- name: Comment lychee report on PR
	if: failure() && github.event_name == 'pull_request'
	uses: marocchino/sticky-pull-request-comment@v2
	with:
	header: lychee
	path: lychee-report.md

	- name: Validate HTML
	uses: Cyb3r-Jak3/html5validator-action@v7.2.0
	with:
	root: _site/
	config: .html5validator.yaml

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