refactor(staged): 首轮结构化流水线门控快照 / bundle full-pipeline schedule snapshot #27

	# 覆盖率：摘要 + 关键目录「行覆盖率」棘轮（fixtures/coverage_ratchet_baselines.json；脚本 scripts/check_coverage_ratchet.py）
	name: code-coverage

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

	concurrency:
	group: ${{ github.workflow }}-${{ github.ref }}
	cancel-in-progress: true

	permissions:
	contents: read

	jobs:
	llvm-cov:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v4

	- name: Install system deps (Wayland headers for rfd / Linux build)
	run: sudo apt-get update && sudo apt-get install -y libwayland-dev

	- uses: dtolnay/rust-toolchain@stable
	with:
	components: llvm-tools-preview

	- uses: Swatinem/rust-cache@v2

	- uses: taiki-e/install-action@v2
	with:
	tool: cargo-llvm-cov@0.6

	- name: cargo llvm-cov (workspace lib JSON summary)
	run: cargo llvm-cov --workspace --lib --json --summary-only --output-path target/llvm-cov-summary.json

	- name: Check coverage ratchet (key directories)
	run: python3 scripts/check_coverage_ratchet.py target/llvm-cov-summary.json

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