Summary

Add a GitHub Actions workflow that detects changes to devcontainer infrastructure files and logs them for prebuild rebuild awareness, enabling teams to understand when and why Codespaces prebuilds are triggered.

Acceptance Criteria

• New workflow file at .github/workflows/devcontainer-change-log.yml
• Triggers on push to main and develop branches
• Path filters include: .devcontainer/**, .github/workflows/copilot-setup-steps.yml
• Workflow logs which infrastructure files changed in the push event
• Workflow outputs a summary annotation visible in the Actions tab
• Optional: Posts a comment or updates a tracking issue when significant infrastructure changes are detected
• Workflow does not block or gate any existing CI pipelines

Technical Details

Monitored Paths

on:
  push:
    branches: [main, develop]
    paths:
      - '.devcontainer/**'
      - '.github/workflows/copilot-setup-steps.yml'

Workflow Behavior

The workflow should:

1. List all changed files matching the infrastructure path filters
2. Categorize changes (base image, features, lifecycle scripts, setup steps)
3. Output a structured summary as a GitHub Actions step summary
4. Optionally notify via issue comment when changes affect prebuild-critical files

This provides visibility into infrastructure drift and helps correlate prebuild rebuild triggers with specific commits.

Dependencies

• feat(devcontainer): configure GitHub Codespaces prebuilds for main and develop #516 — Codespaces prebuilds must be configured for this workflow to provide meaningful prebuild correlation data