Extract shared JS libraries from workflow inline scripts

[jdelfino]

Context

All 8 GitHub Actions workflows embed ~1,800 lines of JavaScript inline in YAML. Much of this logic is duplicated across workflows (config parsing, approval checking, fixes parsing, etc.).

Task

Create shared library modules in .github/agent-workflow/scripts/lib/:

Module	Purpose	Used by
config.js	Parse guardrail config YAML section	All 5 guardrails
approval.js	Check for non-stale PR approval	All 5 guardrails
fixes-parser.js	Parse Fixes #N from PR body	scope, orchestrator, human-review, pr-context
file-patterns.js	isTestFile, isCodeFile, isDependencyFile	test-ratio, dependencies
commit-validator.js	Conventional commit regex validation	commits guardrail
scope-matcher.js	Extract file paths from text, scope matching	scope guardrail
api-patterns.js	API surface regex patterns + detection	api-surface guardrail
patch-parser.js	Parse unified diff line numbers	api-surface guardrail
severity.js	Detect review comment severity	human-review
pr-body.js	Idempotent PR body section replacement	human-review

Each module exports pure functions (no GitHub API calls). All GitHub API interaction stays in the main scripts.

Also set up package.json with js-yaml as a devDependency and node --test as the test script.

Files

• .github/agent-workflow/scripts/lib/*.js (10 new files)
• package.json (new)