Add FAQ last_updated_at check CI step

[MathyouMB]

As a maintainer, I want to enforce that any updates to FAQ pages also update their last_updated metadata so that readers know when the content was last reviewed or changed.

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🧠 Context

Currently, contributors can edit FAQ pages without updating the last_updated field in the frontmatter. This makes it unclear whether the information is still current.

We want to ensure that any time a file in the faq section is modified, its last_updated value is also updated in the same commit.

Example FAQ page structure:

---
title: "What is the COMP 1405 Z Section?"
date: 2024-10-06T00:00:00Z
last_updated: 2024-10-06T00:00:00Z
draft: false
layout: faq-question
summary: "The Z section is an accelerated course that combines the content of COMP 1405 and COMP 1406 into a single term."
contributors:
  - Aditya "Jacc" Padmakar
sources:
  - name: Shopify Dev Degree
    link: https://devdegree.ca/
  - name: Override Requests
    link: https://carleton.ca/registrar/registration/override-requests/
---

We want a CI step to fail the build if a modified FAQ file does not include a change to the last_updated value.

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🛠️ Implementation Plan

1. Write a Node.js script

   • Create a script called check-last-updated.js (or similar)

   • Use git diff --name-only HEAD~1 HEAD to get changed files

   • Filter for files in the faq/ directory (or wherever FAQ content is stored)

   • For each file:

     • Use git diff to check if the last_updated: line has changed
     • If the file was changed but last_updated was not, log an error

2. Add script to CI workflow

   • Create or update a GitHub Actions workflow at .github/workflows/check-faq-updated.yml

   • Add a job that:

     • Checks out the repo
     • Installs Node
     • Runs the script

   • Fail the workflow if any violations are detected

3. Optional: Add friendly error message

   • Instruct contributors to update the last_updated field when modifying FAQ content

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✅ Acceptance Criteria

• A script exists (e.g. check-last-updated.js) that:

  • Detects modified FAQ files
  • Fails if last_updated: is unchanged in a modified file

• A GitHub Actions workflow runs the script on each PR

• The CI fails with a clear message if any FAQ page is modified without updating last_updated

• Only files in the faq/ directory are affected by this rule