ci(book): document the one-time Pages enablement step #4

	name: Build and deploy book

	on:
	push:
	branches: [main]
	# 触发条件刻意保持宽松：mdbook build 只需 ~10 秒，
	# 比维护一份精确路径白名单更省心。
	workflow_dispatch: # 允许在 Actions 页面手动重跑

	permissions:
	contents: read
	pages: write
	id-token: write

	# 同时只允许一个 deploy 在跑
	concurrency:
	group: pages
	cancel-in-progress: false

	jobs:
	build:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout
	uses: actions/checkout@v5

	- name: Install mdBook
	env:
	MDBOOK_VERSION: 0.4.49
	run: \|
	curl -sSL "https://github.com/rust-lang/mdBook/releases/download/v${MDBOOK_VERSION}/mdbook-v${MDBOOK_VERSION}-x86_64-unknown-linux-gnu.tar.gz" \
	\| tar -xz -C /tmp
	sudo mv /tmp/mdbook /usr/local/bin/mdbook
	mdbook --version

	- name: Setup Pages
	uses: actions/configure-pages@v5
	# 注：本仓库 Pages 已通过 `gh api -X POST repos/.../pages -f build_type=workflow` 手动启用。
	# Fork 后首次运行会失败，需在 Settings → Pages 把 Source 设为 "GitHub Actions"，
	# 或对自己的 fork 重跑那条 gh api 命令。

	- name: Build book
	working-directory: ./book
	run: mdbook build

	- name: Upload artifact
	uses: actions/upload-pages-artifact@v3
	with:
	path: ./book/book

	deploy:
	needs: build
	runs-on: ubuntu-latest
	environment:
	name: github-pages
	url: ${{ steps.deployment.outputs.page_url }}
	steps:
	- name: Deploy to GitHub Pages
	id: deployment
	uses: actions/deploy-pages@v4

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