Extract workflow scripts from YAML into standalone JS files

[jdelfino]

Context

Depends on #37 (shared lib modules).

Each workflow's actions/github-script block contains 190-400 lines of inline JavaScript. This should be extracted into standalone .js files.

Task

1. Create main script files in .github/agent-workflow/scripts/:

   • guardrail-scope.js
   • guardrail-test-ratio.js
   • guardrail-dependencies.js
   • guardrail-api-surface.js
   • guardrail-commits.js
   • orchestrator-check.js
   • human-review.js
   • pr-context.js

2. Each file exports module.exports = async function({ github, context, core }) { ... }

3. Import shared lib modules from ./lib/ instead of duplicating logic

4. Slim each workflow YAML to a thin shell:

steps:
  - uses: actions/checkout@v4
  - uses: actions/github-script@v7
    with:
      script: |
        const run = require('./.github/agent-workflow/scripts/guardrail-scope.js');
        await run({ github, context, core });

No functional changes — pure extraction refactor.

Files

• .github/agent-workflow/scripts/*.js (8 new files)
• .github/workflows/*.yml (8 modified — inline JS replaced with require+run)